About me

I belong to a small village Ramwapur Dubey, District-Siddharth Nagar of Uttar Pradesh, India. Currently I am working as a senior visiting Post Doctoral Fellow in Model Team of Nanoelectronics group at IMS Laboratory, University of Bordeaux, Bordeaux, France. Prior to joining the IMS Laboratory, I was working as a Senor Application Engineer in Silvaco Singapore. I also worked as an Assistant Professor of Physics at Central University of Rajasthan (India) and as an Assistant Professor and Coordinator, Centre for Applied Physics at Central University of Jharkhand (India) for a few years.

 I have completed my Ph. D. in Electronics Engineering from Department of Electronics Engineering, IIT, BHU, Varanasi, India. Before that I have earned my M. Sc. Physics with specialization in Electronics from BHU, Varanasi and B. Sc. in Physics, Maths and Chemistry from St. Andrew's College Gorakhpur (D D U Gorakhpur University). I have done my schooling from M. G. Inter College Gorakhpur and Tilak Inter College Bansi, Siddharth Nagar, Uttar Pradesh.

 My research work basically includes modeling, simulation, analysis, fabrication and characterization of photodetectors for all optical applications including guided optical communication (optical fiber communication) and unguided free space optical communication systems in LWIR, MWIR and U.V.-visible regions. It also includes photodetectors for non telecommunication applications such as gas sensors and detection of toxic gases. Modeling and simulation includes, modeling and simulation of infrared photodetectors based on III-V alloys and II-VI alloys for guided optical fiber communication systems and unguided free space optical communication systems respectively. We have modeled different photodetector structures such as photoconductors, p-n photodiodes, p-i-n photodiodes for above applications. Particularly modeling and analysis of InGaAs based photodetectors for optical fiber communication and Hg1-xCdxTe based photodetectors for free space optical communication. For modeling and simulation we use ATLAS device simulator from Silvaco International in which we do virtual wafer fabrication via ATHENA tool of this software and we do device characterization by developing the program in DECKBUILD window of this software. We study the device in terms of its position dependent energy band diagram using BLAZE tool of ATLAS, Electrical characterization through ATLAS and optical characterization through LUMINOUS.

An analytical modeling of N+-InP/n0-In0.53Ga0.47As/p+-In0.53Ga0.47As p-i-n photodetector for guided optical communication has been carried out. The results obtained on the basis of our model have been compared and contrasted with the simulated results using ATLASTM and experimental results reported by others. The photodetector has been studied in respect of energy band diagram, electric field profile, doping profile, dark current, resistance area-product, quantum efficiency, spectral response, responsivity and detectivity by analytical method using closed form equations and also been simulated by using device simulation software ATLASTM from SILVACO® international. Then theoretical analysis of an Hg1-xCdxTe based photoconductive detector has been carried out for characterizing the device in respect of voltage responsivity, quantum efficiency, detectivity and noise equivalent power then its application to study the front end of the receiver for possible application in unguided optical communication in LWIR region in atmospheric window at 9.6µm. The model accounts for all the major recombination mechanisms (e.g., Radiative, Auger, and Shockley-Read-Hall types) including the effect of surface recombination at the interfaces. Subsequently an analytical modeling of p+-Hg0.78Cd0.22Te/n0-Hg0.78Cd0.22Te/CdZnTe, homojunction, P+-Hg0.69Cd0.31Te/n-Hg0.78Cd0.22Te/CdZnTe single heterojunction and N+-Hg0.69 Cd0.31Te /n0- Hg0.78 Cd0.22Te/p+Hg0.78 Cd0.22Te p-i-n photodetectors have been carried out for long wavelength free space optical communication. The results obtained on the basis of our model have been compared and contrasted with the simulated results using ATLASTM from SILVACO® international.

Also fabrication and characterization of an organic photodetector (OPD) in the form of ITO coated glass/Polycarbazole (PCz)/Al Schottky contact has been carried out.The device has been subsequently characterized in respect of electrical and optical properties in order to explore its potential for possible use as a detector in the visible region at 650 nm.

In microelectronics lab we have performed fabrication and characterization of Schottky diode and LPG gas sensors based on Pd/ZnO Schottky contacts. We have also studied the front end receiver circuit based on some photodetectors proposed by us.

We are working on fabrication and characterization of U.V. and visible photodetectors and photovoltaic devices based on ZnO and organic semiconductor materials e.g. polyanthranilic acid (PANA), polycarbazole (PCz), PANA CNT and PCz CNT. So our focus is to explore the potential of organic and inorganic material for fabrication of devices for electronic and optoelectronic applications such as photodetectors, solar cells, LEDs, thin film transistors (TFTs), organic solar cells and organic light emitting diodes (OLEDS) based on organic materials e.g. polymers.