Book/Book Chapter

•  Book Chapter: 

Femtosecond transient absorption Spectroscopy for Organic Photovoltaics by R. Sai Santosh Kumar, and Chinmoy Biswas in digital Encyclopedia of Applied Physics, John Wiley and Sons, 2019 doi.org/10.1002/3527600434.eap825 

• Book: 

R. Sai Santosh Kumar,  Nonlinear Interactions of femtosecond pulses with transparent media: Third order nonlinear optical phenomenon in glasses, crystals and organic molecules, , LAP Lambert Academic Publishing 2011, ISBN-10: 3846528714 | ISBN-13: 978-3846528716 | Publication Date: October 26, 2011

Peer-Reviewed Journals

2024

Journal Papers

1. Rare-earth-doped TiO2 photoanode DSSCs for indoor photovoltaics: a comparative study VR Chappidi, KV Seshaiah, S Madduri, SSK Raavi Journal of Materials Science: Materials in Electronics 35 (7), 528

2. Role of Oxygen Vacancy Migration in Pyroelectric Currents of Nd2Ti2O7 Ceramics as High Temperature Sensors MC Joshi, L Sireesha, SSK Raavi, R Ramadurai IEEE Sensors Journal

3. Harnessing Coherent Light–Matter Interactions for All-Optical Switching and Logic Gate Applications with Macrocyclic Phthalocyanines SK Nayak, MS Ahmed, R Murali, C Barman, KS Srivishnu, L Giribabu, Venugopal Rao Soma, Sai Santosh Kumar Raavi ACS Applied Optical Materials

4. A study on the Raman response of TiO2 upon ion-implantation and annealing in O2 atmosphereK Vemula, VS Katta, S Ojha, F Singh, SSK Raavi Optical Materials 148, 114947

5. "Exotic femtosecond nonlinear optical properties of laser ablated MoS2 quantum dots" SK Nayak, MS Ahmed, M Velpandian, P Meduri, J Rathod, VR Soma,  Sai Santosh Kumar Raavi Optical Materials 147, 114630

2023

Journal Papers

1.        “Deciphering the role of (Er3+/Nd3+) co-doping effect on TiO2 as an improved electron transport layer in perovskite solar cells,” V.S. Katta, R. Dileep, E. Ramasamy, G. Veerappan, and Sai Santosh Kumar Raavi, Solar Energy, vol. 262, 111801 (2023).  

2.        “Enhanced femtosecond nonlinear optical response in Mn-doped Cs2AgInCl6 nanocrystals” Md. Soif Ahmed, SK. Nayak,   L.  Sireesha, J. Rathod,   V. Rao Soma,  Sai Santosh Kumar Raavi , Optics Lettes, vol 48, 35193522 (2023).

3.        “Tunable Near-infrared Emission and Three-Photon Absorption in Lanthanide-doped Double Perovskite Nanocrystals,” Md. Soif Ahmed, L.  Sireesha, S K. Nayak,  R. Bakthavatsalam,   D. Banerjee,   J. Kundu,   V. Rao Soma,  Sai Santosh Kumar Raavi , Nanoscale, vol 15, 9372-9389 (2023). 

4.        “Metalated porphyrin-napthalimide based donor-acceptor systems with long-lived triplet states and effective three-photon absorption,” Md Soif Ahmed, C. Biswas, B. Bhavani, S. Prasanthkumar, D. Banerjee, V. Kumar, P. Chetti, L. Giribabu, V. R. Soma, Sai Santosh Kumar Raavi, Journal of Photochemistry & Photobiology, A: Chemistry, vol 435 114324 (2023).

5.        “Plasmonic Au-NPs embedded Ytterbium-doped TiO2 nanocomposites photoanodes for efficient indoor photovoltaic devices,” V. S. Katta, V. R. Chappidi, Sai Santosh Kumar Raavi, Appl. Surf. Sci. vol 611, 155728 (2023) .

6.        “Tunable Broadband NIR PL Emissions with (Nd3+/Er3+) Codoped TiO2 via Synergetic Energy Transfer” V. S. Katta, C. Biswas, Sai Santosh Kumar Raavi,  ACS Appl. Opt. Mater. Vol. 1, 147–158 (2023).

7.        “Understanding Improved Performance of Vacuum-Deposited All Small-Molecule Organic Solar Cells Upon Postprocessing Thermal Treatment,” S Madduri, V G Kodange, Sai Santosh Kumar Raavi, SG Singh, in IEEE Journal of Photovoltaics, vol. 13, pp. 411-418 (2023)

8.        “Design and Synthesis of Photostable Triphenylamine Based Neutral AIE Nano Luminogens: Specific and Long-Term Tracking of Mitochondria in Cells” T. K. Panda,   K Devarajan,   S. Mayakrishnan,   S. M Basu,   C. Biswas,   M. Chauhan,   U. Hasan,   P. Yuvaraj,   U. M. Narayanan,   Sai Santosh Kumar Raavi ,  J. Giri, Biomater. Sci., vol 11, 3938-3951 (2023).

9.        “Femtosecond nonlinear optical properties of polycyclic aromatic hydrocarbon-based Benzo [e] pyrene derivatives,” S. K. Nayak, R. Kore, Md Soif Ahmed, P. Verma, R. Vallavoju, D. Banerjee, S. Pola, V. R. Soma, P. Chetti, Sai Santosh Kumar Raavi, Opt. Materials, vol. 137, pp 113603 (2023) 

10.     “Enriched visible light absorption by Au-embedded Sm3+ doped TiO2 compact photoanode for enhanced dyesensitized solar cell performance,” V. S. Katta, V. R. Chappidi, A. Kumar, S. Asthana, Sai Santosh Kumar Raavi, Physica B: Condensed Matter vol. 652, 414621 (2023)

11.     “Effect of Electrical Poling on the Structural, Dielectric, and Photoluminescence Properties of Eu3+ Substituted Eco-Friendly Ferroelectric Material Na0.5Bi0.5TiO3,” S. K. Mev, L. Sireesha, Sai Santosh Kumar Raavi, S. Asthana. Materials Science Forum, vol. 1082, pp. 33–40 (2023). 

12."Influence of solvent vapor and thermal annealing on the morphology and performance of solar cells based on PTB7-Th: CPDT-4F active layers". AEX Gavim, R Murali, L Sireesha, M Suresh, SSK Raavi, PB Miranda

13. "Novel metallated imidazole phthalocyanines: synthesis, ultrafast excited-state carrier dynamics and multiphoton absorption properties". Md Soif Ahmed, Kalavala Shivaprakash Srivishnu, Chinmoy Biswas, Dipanjan Banerjee, Prabhakar Chetti, Venugopal Rao Soma, Lingamallu Giribabu, Sai Santosh Kumar Raavi 

2022

Journal Papers

1.        “Ultrafast intramolecular charge transfer dynamics and nonlinear optical properties of phenothiazine-based push–pull zinc porphyrin,” C. Biswas, P.S.Gangadhar, L. Giribabu, P. Chetti, D. Banerjee, V. Rao Soma, Sai Santosh Kumar Raavi, Journal of Photochemistry & Photobiology, A: Chemistry, vol 433 114141 (2022).

2.   Tunable Broadband NIR PL Emissions with (Nd3+/Er3+) Codoped TiO2 via Synergetic Energy Transfer   VS Katta, C Biswas, SSK Raavi ACS Applied Optical Materials 1 (1), 147-158

3.   “Ion-Implantation in Titania-Based Plasmonic Photo-anodes: A Review.” V. Sai Krishna, Sai Santosh Kumar Raavi, Adv. Mater. Interfaces, 2200085 (2022). 

4.   Ultrafast Charge Injection Dynamics in π− Conjugated Zinc Porphyrin and Fullerene bulk heterojunction blend  C Biswas, D Tomar, J Dasgupta, SSK Raavi International Conference on Ultrafast Phenomena, Tu4A. 6

5.  “Defect engineered (Er3+/Nd3+) codoped TiO2 photoanodes for enhanced photoelectrochemical and photovoltaic application,” V. S Katta, M. Velpandian, S. Challapalli, P. Meduri, Sai Santosh Kumar Raavi, Sustainable Energy Fuels, vol 6, 5539-5556 (2022). 

6.  Controlled Modulation of Structure and Luminescent Properties of Zero Dimensional Manganese Halide Hybrids through Structure-directing Metal Ion, D. K Das, R. Bakthavatsalam, V. N. Kumar, B. P Mali, Md Soif Ahmed, Sai Santosh Kumar Raavi, P. Raghaviah, J. Kundu, Inorganic Chemistry, vol. 61, pp 5363-5372 (2022). 

7.   Femtosecond Excited-State Dynamics and Ultrafast Nonlinear Optical Investigations of Ethynylthiophene Functionalized Porphyrin, Chinmoy Biswas, V. R. Soma, L. Giribabu, and Sai Santosh Kumar Raavi, Opt. Materials, vol. 127, pp 112232 (2022)

8.  Synergistic electronic coupling/cross-talk between the isolated metal halide units of zero dimensional heterometallic (Sb, Mn) halide hybrid with enhanced emission, A. Biswas, R. Bakthavatsalam, D. K Das, J. Sam, B. P Mali, C. Biswas, N. Maana, S. Thomson, Sai Santosh Kumar Raavi, S. Kurungot, R. G Gonnade, S. Dutta, J. Kundu, J. Mater. Chem. C, vol. 10, 360-370 (2022).  DOI: 10.1039/D1TC04704C IF: 8.067

9.  “Femtosecond Third-Order Non-Linear Optical Properties of Unconstrained Green Fluorescence Protein Chromophores,” Md Soif Ahmed, C. Biswas, D. Banerjee, P. Chetti, J. -S. Yang, V. R. Soma, Sai Santosh Kumar Raavi, Front. Phys. 10:914135 (2022). DOI: 10.3389/fphy.2022.914135 .  IF: 3.718

10.  Nonlinear optical techniques for characterization of organic electronic and photonic devices, Md Soif Ahmed, Chinmoy Biswas, Paulo B Miranda, Sai Santosh Kumar Raavi, Eur. Phys. J. Spec. Top. vol. 231, pages1–17 (2022). DOI: 10.1140/epjs/s11734-021-00391-8   IF: 2.891

11.    Enhanced electrical and photocatalytic activities in Na0.5Bi0.5TiO3 through structural modulation by using anatase and rutile phases of TiO2, C. Goutham, K.V. Ashok Kumar, Sai Santosh Kumar Raavi, Ch. Subrahmanyam, S. Asthana, J. Materiomics vol. 8, pp 18-29 (2022) DOI: 10.1016/j.jmat.2021.06.003       IF: 8.589

12.  Structural, impedance, and photoluminescence properties of Ho3+ substituted Na0·5Bi0·5TiO3, A. Kumar, T. Durga Rao, V. S. Katta, Sai Santosh Kumar Raavi, Saket Asthana, Physica B: Condensed Matter, vol 639,413926 (2022) DOI: 10.1016/j.physb.2022.413926  IF: 2.988

13.  “Synthesis, characterization, structural and photophysical properties of heteroleptic ruthenium complexes containing 2-(1H-benzo[d]imidazol-2-yl)quinoline ligand towards electrocatalytic CO2 reduction” S. Kumbhakar, B. Giri, A. Muley, K. S. Karumban, C. Biswas, Sai Santosh Kumar Raavi, S. Maji J. Chem. Sci. vol. 134, 71 (2022). DOI: 10.1007/s12039-022-02063-z. IF: 2.15   

International Conference Proceedings (Scopus Indexed)

14.        “Superior Three-Photon Absorption and Ultrafast Nonlinear Photonic Switching Response of Double Perovskite Cs2AgInCl6 Nanocrystals,” Md Soif Ahmed, S. Lavadiya, S. K. Nayak, D. Banerjee, V. R. Soma, and Sai Santosh Kumar Raavi, in Frontiers in Optics + Laser Science 2022 (FIO, LS), Technical Digest Series (Optica Publishing Group, 2022).

15.        “Ultrafast Nonlinear Optical Studies of Polycyclic Aromatic Hydrocarbon (PAHs) based Benzo [b] naphtho [1, 2,

3, 4-pqr] Perylene using Femtosecond Z-scan,” S. K. Nayak, M. S. Ahmed, S. Pola, D. Banerjee, V. R. Soma, P. Chetti, and Sai Santosh Kumar Raavi in Frontiers in Optics + Laser Science 2022 (FIO, LS), Technical Digest Series (Optica Publishing Group, 2022).

16.     “Excited State Dynamics and Nonlinear Optical Responses of Metalated Porphyrin-Napthalimide Based DonorAcceptor Systems,” Md Soif Ahmed, C. Biswas, B. Bhavani, L. Giribabu, V. R. Soma, Sai Santosh Kumar Raavi in Proceedings of the 2022 Conference on Lasers and Electro-Optics Pacific Rim (Optica Publishing

Group, 2022),

17.     "Ultrafast Excited State Dynamics of Triphenyl Imidazole Thiophene Substituted Phthalocyanines," M. S. Ahmed, C. Biswas, K. S. Srivishnu, L. Giribabu, V. R. Soma, and Sai Santosh Kumar Raavi, in The International Conference on Ultrafast Phenomena (UP) 2022, F. Légaré, T. Tahara, J. Biegert, T. Brixner, and N. Dudovich, eds., Technical Digest Series (Optica Publishing Group, 2022).

18.     “Ultrafast Photoexcited Molecular Dynamics of Metalated Porphyrin – Napthalimide Based Donor-Acceptor Systems” Md Soif Ahmed, Chinmoy Biswas, Dipanjan Banerjee, Botta Bhavani, S. Prasanthkumar, Lingamallu Giribabu, Venugopal Rao Soma, and Sai Santosh Kumar Raavi, in Conference on Lasers and Electro-Optics, Technical Digest Series (Optica Publishing Group, 2022), paper JW3B.4.

2021

Journal Papers

1.     Femtosecond Excited-State Dynamics and Ultrafast Nonlinear Optical Investigations of Ethynylthiophene Functionalized Porphyrin, Chinmoy Biswas, V. R. Soma, L. Giribabu, and Sai Santosh Kumar Raavi, Opt. Materials, vol. 127, pp 112232 (2022) .

2.   Enhanced broadband emission of co-doped (Nd-Er) TiO2 VS Katta, C Biswas, SSK Raavi Frontiers in Optics, JW7A. 76

3.  Femtosecond Excited State Dynamics of Phenanthroimidazole Derivative Molecules Through Excited State Intramolecular Proton Transfer C Biswas, K Devarajan, P Dey, TK Panda, S Krishnan, SSK Raavi Laser Science, JW7A. 75

4.  Effect of electrical poling on the structural, dielectric and photoluminescence properties of small concentration of Ho+ 3 substituted NBT  A Kumar, VS Katta, SSK Raavi, S Asthana Journal of Physics: Conference Series 2070 (1), 012016

5.  Er3+ doped titania photoanode for enhanced performance of photo-electrochemical water splitting devices Venkata Seshaiah Katta, M Velpandian, Vishnuvardhan Reddy Chappidi, Md Soif Ahmed, Abhinav Kumar, Saket Asthana, Praveen Meduri, Sai Santosh Kumar Raavi  Materials Letters 302, 130297

6.  Ultrafast Excited State Relaxation Dynamics of New Fuchsine-a Triphenylmethane Derivative Dye C Biswas, V Rao Soma, P Chetti, S Santosh Kumar Raavi ChemPhysChem 22 (24), 2562-2572

7. Samarium-doped TiO2 photoanodes for the molecular devices for solar energy conversion VS Katta, VR Chappidi, SSK Raavi  Photonics for Energy 11893, 10-19

8.   Annealing induced control of trap-assisted recombination in vacuum-deposited small-molecule solar cells S Madduri, VS Katta, SSK Raavi, SG Singh Materials Letters 300, 130159

9.  Lanthanide doped Titania photoanodes for enhanced performance of Indoor light energy harvesting DSSC devices VS Katta, VR Chappidi, SSK Raavi Novel Optical Materials and Applications, JTu1A. 40

10.  Femtosecond nonlinear optical properties of-conjugated diketopyrrolopyrrole substituted porphyrin  molecules C Biswas, SV Rao, SSK Raavi Novel Optical Materials and Applications, JTu1A. 39

11. Optimization of thermally evaporated small molecule ternary organic solar cells S Madduri, VG Kodange, SSK Raavi, SG Singh 2021 IEEE 48th Photovoltaic Specialists Conference (PVSC), 0732-0736

12.  Femtosecond transient absorption studies of two novel energetic tetrazole derivatives NK Katturi, C Biswas, N Kommu, SSK Raavi, VR Soma Chemical Physics Impact 2, 100016

13.  Samarium-doped TiO2photoanodes for the molecular devices for solar energy conversion SSK Raavi SPIE

14.  Enhanced broadband emission of co-doped (Nd-Er) TiO2 SSK Raavi Optica Publishing Group (formerly OSA)

15.  Femtosecond nonlinear optical properties of π-conjugated diketopyrrolopyrrole substituted porphyrin molecules SSK Raavi The Optical Society

16.  Femtosecond Excited State Dynamics of Phenanthroimidazole Derivative Molecules Through Excited State Intramolecular Proton Transfer TK Panda, SSK Raavi Optica Publishing Group (formerly OSA)

17.  Comparative photophysical and femtosecond third-order nonlinear optical properties of novel imidazole substituted metal phthalocyanines SSK Raavi Elsevier Ltd

18.  The metal halide structure and the extent of distortion control the photo-physical properties of luminescent zero dimensional organic-antimony (III) halide hybrids SSK Raavi Royal Society of Chemistry

19.  Optical Coherence and Quantum Storage via EIT: A Brief Study of Open Quantum System D Mishra, SSK Raavi IIT HYDERABAD

20.  Ultrafast electron injection kinetics and effect of plasmonic silver nanoparticle at organic dye-TiO2 interface SSKR C. Biswas, M. S. Ahmed Asian Journal of Physics 30 (6), 933-946

21.  Lead-free zero dimensional tellurium (iv) chloride-organic hybrid with strong room temperature emission as a luminescent material A Biswas, R Bakthavatsalam, V Bahadur, C Biswas, BP Mali, SSK Raavi, Journal of Materials Chemistry C 9 (12), 4351-4358.

22. Vacancies induced enhancement in neodymium doped titania photoanodes based sensitized solar cells and photo-electrochemical cells Venkata Seshaiah Katta, Aparajita Das, Goutham Cilaveni, Supriya Pulipaka, Ganapathy Veerappan, Easwaramoorthi Ramasamy, Praveen Meduri, Saket Asthana, Deepa Melepurath, Sai Santosh Kumar Raavi.

23.  Comparative photophysical and femtosecond third-order nonlinear optical properties of novel imidazole substituted metal phthalocyanines Somdatta Bhattacharya, Govind Reddy, Sneha Paul, Sk Saddam Hossain, Sai Santosh Kumar Raavi, Lingamallu Giribabu, Anunay Samanta, Venugopal Rao Soma  

24. The metal halide structure and the extent of distortion control the photo-physical properties of luminescent zero dimensional organic-antimony (iii) halide hybrids  Anupam Biswas, Rangarajan Bakthavatsalam, Bhupendra P Mali, Vir Bahadur, Chinmoy Biswas, Sai Santosh Kumar Raavi, Rajesh G Gonnade, Janardan Kundu 

2020

Journal Papers

1.  “Multistep Electron Injection Dynamics and Optical Nonlinearity Investigations of π-Extended Thioalkyl-Substituted Tetrathiafulvalene Sensitizers,” Chinmoy Biswas, N. K. Katturi, N. Duvva, L. Giribabu, V. R. Soma, and Sai Santosh Kumar Raavi, J. Phys. Chem. C,  vol. 124, 24039–24051 (2020).

2.  “A photoanode with Plasmonic Nanoparticles of Earth Abundant Bismuth for Photoelectrochemical Reactions,“  P. Subramanyam, M. Deepa, Sai Santosh Kumar Raavi, H. Misawa, V. Biju, and Ch. Subrahmanyam, Nanoscale Adv., 2, 5591-5599 (2020). 

3. “Femtosecond Transient Absorption Spectroscopy Studies of Ethynylthiophene Functionalized Porphyrin” Chinmoy Biswas, K. N. Krishnakanth, N. V Krishna, L Giribabu, S. Venugopal Rao, and Sai Santosh Kumar Raavi, Frontiers in Optics / Laser Science.

4. “Enhanced Broadband Emission in Novel Phenanthroimidazole Derivative Molecules via Excited State Intramolecular Proton Transfer,” Chinmoy Biswas, K. Devarajan, T. K Panda, and Sai Santosh Kumar Raavi, NOMA, OSA Advanced Photonics Congress (AP) 2020, OSA Technical Digest (2020). 

5. “SPR induced photoluminescence quenching in MAPbBr3-QD/TiO2 interface,” V.S. Katta, L. Chouhan, V. Biju, Sai Santhosh Kumar Raavi, PVLED, OSA Advanced Photonics Congress (AP) 2020, OSA Technical Digest, (2020). 

7.“Organic photovoltaics: “Towards Development of Low-cost Green Solar Cell Technology,” Sai Santosh Kumar Raavi, Energy Future, vol. 8, 59-62 (2020).

8.“Ultrafast nonlinear optical properties and excited-state dynamics of Soret-band excited D-π-D porphyrins,” N. K. Katturi, Govind Reddy, C. Biswas, Sai Santosh Kumar Raavi, L. Giribabu, V. R. Soma, Opt. Materials, vol. 107. 110041 (2020).

9.  “Ultrafast Photophysical and Nonlinear Optical Properties of Novel Free Base and Axially Substituted Phosphorus(V) Corroles,” N. K. Katturi, B. Shivaprasad, A.R. Ramya, C. Biswas, Sai Santosh Kumar Raavi, K. Giribabu, V. R. Soma, J. of Mol. Liquids, vol 311, 113308 (2020) 

10.     Ligand Structure Directed Dimensionality Reduction (2D→ 1D) in Lead Bromide Perovskite, Rangarajan Bakthavatsalam, Muhammed PU Haris, Samir R Shaikh, Amruta Lohar, Ashutosh Mohanty, Dhanashree Moghe, Shivani Sharma, Chinmoy Biswas, Sai Santosh Kumar Raavi, Rajesh G Gonnade, Janardan Kundu, J. Phys. Chem. C, vol. 124, 1888-1897 (2020). 

11.     “A simple D–π–A system of phenanthroimidazole-π-fluorenone for highly efficient non-doped bipolar AIE luminogens: synthesis, and molecular optical, thermal and electrochemical properties” D. Kathirvelan, S. Mayakrishnan, N. Uma Maheswari, Chinmoy Biswas,  Sai Santosh Kumar Raavi and Tarun K. Panda, New Journal of Chemistry vol. 44, 1785-1794 (2020). 

12.     “Ultrafast photophysical studies and femtosecond third-order nonlinear optical properties of a Soret-band excited zinc phthalocyanine,”  N. K. Katturi, V. S. K. Jonnadula, C. Biswas, Sai Santosh Kumar Raavi, L. Giribabu, V. R. Soma, Proc. SPIE 11365, Organic Electronics and Photonics: Fundamentals and Devices II, 113650W (2020). 

13.  Ultrafast nonlinear optical properties and excited-state dynamics of Soret-band excited D-π-D porphyrins SSK Raavi Elsevier BV.

14.  Том. 11365. Organic Electronics and Photonics: Fundamentals and Devices II.-Сер. Organic Electronics and Photonics: Fundamentals and Devices II NK Katturi, C Biswas, VR Soma, SSK Raavi, VSK Jonnadula, L Giribabu, N Nekrasov, A Emelianov, I Bobrinetskiy, D Kireev, N Omerović 

15. Femtosecond to Microsecond Excited State Dynamics of a Novel Zinc Phthalocyanine Using Transient Absorption Spectroscopy  Somdatta Bhattacharya, Sneha Paul, Sk Saddam Hossain, Sai Santosh Kumar Raavi, Giribabu Lingamallu, Venugopal Rao Soma, Anunay Samanta 

International Conference Proceedings 

• "Ultrafast Photophysical Investigations of water-soluble triphenylmethane derivative (New Fuchsin) molecule," C. Biswas, S. Bhattacharya, V. R. Soma and Sai Santosh Kumar Raavi, in The 22nd International Conference on Ultrafast Phenomena 2020.

• “Plasmon Induced Ultrafast Excited State Interfacial Electron Dynamics of Tetrathiafulvalene Sensitizers,” Chinmoy Biswas, N. K. Katturi, N. Duvva, L. Giribabu, V. R. Soma, and Sai Santosh Kumar Raavi,  in The 22nd International Conference on Ultrafast Phenomena 2020, F. Kärtner, M. Khalil, R. Li, F. Légaré, and T. Tahara, eds., OSA Technical Digest (Optical Society of America, 2020).

2019

Journal Papers

1.        “Low Cost ‘Green’ Dye Sensitized Solar Cells Based on New Fucshin dye with Aqueous Electrolyte and Platinum-free Counter Electrodes” Ramesh K. Kokal, S. Bhattacharya, L. S. Cardoso,  Paulo B. Miranda,  S. Venugopal Rao, Ch. Prabhakar,  Melepurath Deepa, Sai Santosh Kumar Raavi , Solar Energy vol. 188, 913923  (2019).

2.        “Quantum Dot Donor-Polymer Acceptor Architecture for a FRET Enabled Solar Cell,” Ramesh Kokal, Sai Santosh Kumar Raavi, M. Deepa, ACS Applied Materials & Interfaces, vol. 11, 18395-18403 (2019). 

3.        “Linear and Femtosecond Nonlinear Optical Properties of Soluble Pyrrolo[1,2-a] Quinoxalines,” C. Biswas, K. N. Krishnakanth, J. J. Lade, A.C. Chaskar,  Anuj Tripathi, Chetti Prabhakar, S. Venugopal Rao, Sai Santosh Kumar Raavi, Chemical Physics Letters, vol. 730. 638-642 (2019) 

4.        “Optoelectronic, femtosecond nonlinear optical properties and excited state dynamics of a triphenyl imidazole induced phthalocyanine derivative" S. Bhattacharya, Chinmoy Biswas, Sai Santosh Kumar Raavi, J. V. S. Krishna, D. Koteswars Rao, L. Giribabu, Venugopal Rao Soma, RSC Advances, vol. 9, 36726-36741 (2019) .

5.        “Ultrafast excited state dynamics and femtosecond nonlinear optical properties of laser fabricated Au and Ag50Au50 nanoparticles,” K.N. Krishnakanth, Byram Chandu, M.S.S. Bharathi, Sai Santhosh Kumar Raavi, S. Venugopal Rao, Opt. Materials, vol. 95. 109239 (2019).  

6.        “Femtosecond Transient Absorption and Nonlinear Optical Studies of a Novel Zinc Phthalocyanine,” Somdatta Bhattacharya, Chinmoy Biswas, Sai Santosh Kumar Raavi, Giribabu Lingamallu, Venugopal Rao Soma,  Nonlinear Optics (NLO), OSA Technical Digest (Optical Society of America, 2019).    

7.        "Synthesis, Optical, Electrochemical, DFT Studies, NLO Properties and Ultrafast Excited State Dynamics of Carbazole Induced Phthalocyanine Derivatives" S. Bhattacharya, Chinmoy Biswas, Sai Santosh Kumar Raavi, J. V. S. Krishna, N. Vamsi Krishna, L. Giribabu, Venugopal Rao Soma, J. Phys. Chem. C, vol. 123, 1111811133 (2019). 

8.        “Luminescent zinc(II) selone macrocyclic ring,” G. Prabusankar, G. Raju, M. Vaddamanu, N. Muthukumaran, A. Sathyanarayana, S. Nakamura, Y. Masaya, K. Hisano, O. Tsutsumi, C. Biswas, Sai Santosh Kumar Raavi, RSC Advances, vol. 9, 14841-14848 (2019).

9.        “Control over relaxor, piezo-photocatalytic and energy storage properties in Na0.5Bi0.5TiO3 via processing methodologies,” C. Goutham,  K.V. Ashok Kumar, Sai Santhosh Kumar Raavi, Ch. Subrahmanyam and Saket Asthana, J. Alloys Comp, , vol. 798, pp 540- 552(2019). 

 International Conference Proceedings 

•  “Particle size dependent properties of Na0.5Bi0.5TiO3 synthesized using hydrothermal technique,” C. Goutham,  Sai Santhosh Kumar Raavi, and Saket Asthana AIP Conference Proceedings 2082, 030010 (2019).

2018

Journal Papers

1.        “Multifunctional Nd3+ substituted Na0.5Bi0.5TiO3 as lead-free ceramics with enhanced luminescence, ferroelectric and energy harvesting properties,” K.R. Kandula, Saket Asthana and Sai Santosh Kumar Raavi,  RSC Advances, vol. 8, 15282-15289 (2018). 

2.        “Improved electrical and photoluminescence properties in Nd substitution of 0.94(Na 0.5 Bi 0.5 TiO 3 )-0.06BaTiO 3 lead free multi-functional ceramics,” K. R. Kandula, K. Banerjee, Sai Santhosh Kumar Raavi, and Saket Asthana, Adv. Mater Lett. vol. 9, 652-655 (2018). 

3.        “ Enhanced electrocaloric effect and energy storage density of Nd-substituted 0.92NBT-0.08BT lead free ceramic,” K.R. Kandula, K. Banerjee, Sai Santosh Kumar Raavi,  and Saket Asthana, Phys. Stat. Sol. A, vol. 215,  pp 1700915 (2018).  

4.        “Correlation between structural, ferroelectric and luminescence properties through compositional dependence of Nd3+ ion in lead free Na0.5Bi0.5TiO3” K.R. Kandula, Sai Santosh Kumar Raavi,  and Saket Asthana, J. Alloys Comp, , vol. 732, pp 233-239 (2018).

 Internatinal Conference Proceedings 

•  “Improved ferroelectric and photoluminescence properties in Pr3+ substituted Na0.5Bi0.5TiO3 synthesized using hydrothermal route”, C. Goutham, K. R. Kandula, Sai Santhosh Kumar Raavi, and Saket Asthana, AIP conference proceedings vol. 1942, 030011 (2018).

• "A lead free 0.96(Na0.5Bi0.49Nd0.01TiO3) -0.04BaTiO3 piezoceramic for possible optoelectronic device applications", K. R. Kandula, K. Banerjee, Sai Santhosh Kumar Raavi, and Saket Asthana, AIP conference proceedings vol. 1942, 050130 (2018).     

2017

Journal Papers

1.        “The effect on electrical and luminescent properties in nanocrystalline Na0.5Bi0.5TiO3,” Thirupathi G., Kumara Raja Kandula , Sai Santosh Kumar Raavi, Saket Asthana, Mater. Res. Express, vol. 4, art: 095019 (2017).

2.        “Enhancement in electrical and optical properties by substitution of lanthanides (Nd3+ and Eu3+) in lead free Na0.5Bi0.5TiO3 ceramics”, K.R. Kandula,  Sai Santosh Kumar Raavi,, Saket Asthana,  Ferroelectrics , vol. 518, pp 23-30 (2017). 

2015

Journal Papers

1. “Small-Size Effects on Electron Transfer in P3HT/InP Quantum Dots,” J. Yin, M. Kumar, Q. Lei, L. Ma, Sai Santosh Kumar Raavi, G. G Gurzadyan, C. Soci, J. Phys. Chem. C, vol 119, pp 26783–26792 (2015). 

2. “Femtosecond to Microsecond Dynamics of Soret-Band Excited Corroles,” Sai Santosh Kumar Raavi, J. Yin, G. Grancini, C. Soci, V. R. Soma, G. Lanzani, and L. Giribabu, J. Phys. Chem. C, vol 119, pp. 28691-28700 (2015). 

2014​

Journal Papers

1. “Triple bulk heterojunctions as means for recovering the microstructure of photoactive layers in organic solar cell devices”  Z. Kan,  L. Colella,  E V. Canesi,  G. Lerario,  R. Sai Santosh Kumar,  V. Bonometti, P. R. Mussini,  G. Cavallo, G. Terraneo,  P. Pattanasattayavong,  T. D. Anthopoulos,  C. Bertarelli,  and P. E.Keivanidis, Sol. Energ. Mat. Sol. Cells, vol. 120, 37 − 47 (2014).  

2.  “Focus issue introduction: Renewable energy and the environment 2013” R. John Koshel, Christian Seassal, Olivier Deparis, and Sai Santosh Kumar Raavi, Opt. Express, vol. 22, pp. A561-A563 (2014). 

3.  “Impact of Molecular Charge-Transfer States on Photocurrent Generation in Solid State Dye-Sensitized Solar Cells Employing Low-Band-Gap Dyes” Sai Santosh Kumar Raavi, P. Docampo, C. Wehrenfennig, M. J. P.Alcocer,  G. Sadoughi, L. M. Herz, H. J. Snaith, and A. Petrozza, J Phys. Chem C, vol.  118, pp 16825–16830 (2014). 

4.  “Photoactive molecular junctions based on self-assembled monolayers of indoline dyes,” L. Caranzi, G. Pace, S. Guarnera, E.V. Canesi, L. Brambilla, Sai Santosh Kumar Raavi, A. Petrozza, and M. Caironi, ACS Appl. Mater. Interfaces, vol. 6, 19774-19782 (2014). 

5. “Ultrafast charge photogeneration in low band-gap semiconducting polymer based solid-state dye sensitized solar cell (sDSC), Sai Santosh Kumar Raavi, G. Grancini, J. Yin, C. Soci, A. Petrozza, H. J. Snaith, and G. Lanzani, in Light, Energy and the Environment, OSA Technical Digest (online) (Optical Society of America, 2014), paper PTu4B.5. doi.org/10.1364/PV.2014.PTu4B.5

International Conference Proceedings 

• “Femtosecond to nanosecond excited stated dynamics of novel corroles,” Sai Santosh Kumar Raavi, J. Yin, G.Grancini, C. Soci, V. R. Soma, G. Lanzani, and L. Giribabu, 12th  International Conference on Fiber Optics and Photonics,  SA Technical Digest (online),Optical Society of  America 2014).

Before JOINING IIT Hyderabad

2013

Journal Papers

1.  “Ultrafast Energy Transfer in Ultrathin Organic Donor/Acceptor Blend,” A.R. Srimath Kandada, G. Grancini, A. Petrozza, S. Perissinotto, D. Fazzi, R. Sai Santosh Kumar and G. Lanzani, Sci. Rep., vol. 3, article: 2073 (2013).

2.   “Effect of Polymer Morphology on P3HT-based solid-state dye sensitized solar cells: an ultrafast spectroscopic investigation,” R. Sai Santosh Kumar, G. Grancini, A. Petrozza, A. Abrusci, H.J. Snaith and G. Lanzani, Opt. Express, vol. 21, 469-474 (2013). 

3.  “Panchromatic “Dye-Doped” Polymer Solar Cells: From Femtosecond Energy Relays to Enhanced PhotoResponse,” G. Grancini,  R. Sai Santosh Kumar, M. Maiuri, J. Fang, W.T. S. Huck,  M. Alcocer,  G. Lanzani,  A. Petrozza,  G. Cerullo and H.J. Snaith, J. Chem Phys Lett. vol. 4, 442-447 (2013). 

​2012​

Journal Papers

1.  "Boosting Infrared Light Harvesting by Molecular Functionalization of Metal Oxide/Polymer Interfaces in Efficient Hybrid Solar Cells," G. Grancini, R. Sai Santosh Kumar, A. Abrusci, H. L. Yip, C.-Z. Li, A. K. Y. Jen, G. Lanzani and H. J. Snaith, Adv. Fun. Mat. vol. 22, 2160–2166 (2012)  

2.  “Effect of Selective Interactions at the Interface of Polymer-Oxide Hybrid Solar Cells,” E. V. Canesi,  M. Binda,  A. Abate,  S. Guarnera,  L. Moretti,  V. D'Innocenzo,  R. Sai Santosh Kumar,  A. Abrusci,  H. Snaith,  A. Mattoni,  G. Lanzani and A. Petrozza, Energy Environ. Sci. vol. 5, 9068-9076 (2012). 

2011​​

Journal Papers

1. “Primary photo-events in a metastable photomerocyanine,” R. Sai Santosh Kumar, L. Lüer, D. Polli, M. Garbugli and G. Lanzani. Opt. Mat. Express, vol. 1, 293- 304 (2011).

2.  “Ultrafast Dynamics of Exciton Fission in Polycrystalline Pentacene,” M. W.B. Wilson, A. Rao1, J. Clark, R. Sai Santosh Kumar, D. Brida, G. Cerullo and R. H. Friend, J. Am. Chem. Soc., vol. 133, 11830-11833 (2011) .

3.  “ Influence of ion induced local Coulomb field and polarity on charge generation and efficiency in Poly (3Hexylthiophene) -based solid-state dye-sensitized solar cells,” A. Abrusci, R. Sai Santosh Kumar, Md. AlHashimi, M. Heeney, A. Petrozza and H. J. Snaith, Adv. Fun. Mat. vol. 21, 2571–2579 (2011) .

2010​

Journal Papers

1.  “Plasmonic Dye-Sensitized Solar Cells Using Core-Shell Metal-Insulator Nanoparticles,” M. D. Brown, T.Suteewong, R. Sai Santosh Kumar, V. D’Innocenzo, A. Petrozza, M. M. Lee, U. Wiesner, and H. J. Snaith, Nano Letters, vol. 11 438-445 (2010).

2009​

Journal Papers

1.  “Optical studies of two dimensional gratings in fused silica, GE 124, and Foturan™ glasses fabricated using femtosecond laser pulses” K.C. Vishnubhatla, S. Venugopal Rao, R. Sai Santosh Kumar, M. Ferrari and D. Narayana Rao, Opt. Commun. vol. 282, 4537-4542 (2009).

2.  “Femtosecond laser direct writing of gratings and waveguides in high quantum efficiency erbium-doped Baccarat glass” K C Vishnubhatla, S Venugopal Rao, R Sai Santosh Kumar, R Osellame, S N B Bhaktha, S Turrell, A Chiappini, A Chiasera, M Ferrari, M Mattarelli, M Montagna, R Ramponi, G C Righini and D Narayana Rao,  J. Phys. D: Appl. Phys. vol. 42 205106 (2009). 

3. “Ultrafast nonlinear optical properties of alkyl phthalocyanines investigated using degenerate four-wave mixing technique“ R. Sai Santosh Kumar, S. Venugopal Rao, L. Giribabu, and  D. Narayana Rao,  Opt. Mater. vol.  31, 1042-1047 (2009). 

2008

Journal Papers

1.   “Four wave mixing at air-dielectric interfaces with a femtosecond laser excitation” R. Sai Santosh Kumar, Suneel    Singh,    and    D. Narayana Rao, Opt.Express    vol.16,18034-18039   (2008).

2. “Depolarization properties of the femtosecond supercontinuum generated in condensed media” R. Sai Santosh Kumar, K. L. N. Deepak, and D. Narayana Rao,  Phys. Rev. A vol. 78, 043818  (2008) 

3. “Control of the polarization properties of supercontinuum generation in a noncentrosymmetric crystal”, R. Sai Santosh Kumar, K. L. N. Deepak, and D. Narayana Rao,  Opt. Lett. vol. 33, 1198-1200 (2008) 

4. “Linear and Nonlinear Optical Properties of Mesoionic Oxyallyl Derivatives: Enhanced Non-Resonant Third Order Optical Nonlinearity in Croconate Dyes”,  Ch. Prabhakar, K. Yesudas, K. Bhanuprakash , V. Jayathirtha Rao,  R.  Sai Santosh Kumar, and D. Narayana Rao, J. Phys Chem. C, vol. 112  , 13272-13280 (2008)

5. “Nonlinear optical properties of alkyl phthalocyanines in the femtosecond, nanosecond, and cw excitation regimes”, R. Sai Santosh Kumar, S. Venugopal Rao, L. Giribabu, and D. Narayana Rao  Proc. SPIE, vol. 6875, 68751D (2008) 

6. “ Inscription and characterization of micro-structures in silicate, FOTURAN and tellurite glasses by femtosecond laser direct writing,” K. C. Vishnubhatla, S. Venugopal Rao, R. Sai Santosh Kumar, K. Shiva Prasad, P. S. R. Prasad, and D. Narayana Rao, Proc. SPIE vol. 6881, 688113 (2008) 

7. “Micro-Raman mapping of micro-gratings in BACCARAT glass directly written using femtosecond laser,” K. C. Vishnubhatla, S. Venugopal Rao, R. Sai Santosh Kumar, S. N. B. Bhaktha, A. Chiappini, A. Chiasera, J. Laureyns, M. Ferrari, M. Mattarelli, M. Montagna, R. Osellame, R. Ramponi, G. C. Righini, S.Turrell, and D. Narayana Rao, Proc. SPIE vol. 6881, 688114 (2008) 

2007

Journal Papers

1.  “Broadband supercontinuum generation in a single Potassium Di-hydrogen Phosphate (KDP) crystal achieved in tandem with sum frequency generation” R. Sai Santosh Kumar , S. Sree Harsha, and D. Narayana Rao,  Appl. Phys. B. vol. 86, 615-621 (2007).

2. “Femtosecond and nanosecond nonlinear optical properties of alklyphthalocyanines studied using Zscan”, R. Sai Santosh Kumar, S. Venugopal Rao, L. Giribabu, and D. Narayana Rao, Chem. Phys. Lett. vol. 447, 274- 278 (2007) 

3.  “Second harmonic generation and crystal growth of new chalcone derivatives”, P.S. Patil; S.M. Dharmaprakash; K. Ramakrishna, H.-K. Hoong-Kun Fun, R. Sai Santosh Kumar, and D. Narayana Rao, Journal of Crystal Growth, vol. 303, 520-524, 2007.  

2006​

Journal Papers

1. “Nonlinear absorption and scattering properties of cadmium sulphide nanocrystals with its application as a potential optical limiter”, N. Venkatram, R. Sai Santosh Kumar, and D. Narayana Rao, J. Appl. Phys. vol. 100, 074309-1–074309-8 (2006).  

2. “Nonlinear optical absorption characterization and optical switching of Au nanoparticle doped SiO2-TiO2 sol-gel films” N. Venkatram, R. Sai Santosh Kumar, S. K. Medda, Sucheta De, Goutam De, and D. Narayana Rao, Journal of Nanoscience and Nanotechnology, vol.  6, 1990–1994 (2006).