Conferences

· LAOP 2018 (OSA Latin America Optics & Photonics Conference), Lima, Peru:

A. Tejada, S. Braunger, L. Kegelmann, S. Albrecht, J. A. Töfflinger, L. Korte and J. A. Guerra, "Determination of the complex refractive index, optical bandgap and Urbach energy of CH₃NH₃PbI₃ and FA_1-yCs_yPb(I_1-xBr_x)₃ perovskite thin films", poster.

· B-MRS 2018 (XVII Brazil Materials Research Society Meeting), Natal, Brazil:

A. Tejada, S. Braunger, L. Korte, S. Albrecht, B. Rech, J. A. Töfflinger, R. Grieseler, and J. A. Guerra, "Optical and bandgap characterization of formamidinium cesium lead mixed halide FA_0.83Cs_0.17Pb(I_{1 - x}Br_x)₃ perovskite thin films", talk.

P. Llontop, A. Tejada, C. E. Torres, M. Mejia, J. Dulanto, L. Conde, F. Rumiche, J. A. Töfflinger, R. Grieseler, and J. A. Guerra, "Thermal activation of the luminsecent properties of Tb-doped ITO thin films", talk.

· JOPES 2018 (Jornadas Peruanas de Energía Solar), Lima, Perú:

L. Flores, K. Tucto, A. Töfflinger, J. A. Guerra and R. Grieseler, "Investigation of Tb³⁺/Yb³⁺co-doped oxide glasses thin films for down-conversion", poster.

A. Tejada, S. Braunger, L. Korte, S. Albrecht, B. Rech, J. A. Töfflinger, R. Grieseler, and J. A. Guerra, "Optical and bandgap characterization of perovskite thin films for tandem solar cells", poster.

· EURODIM 2018 (Europhysical Conference on Defects in Insulating Materials), Bydgoszcz, Poland:

Loreleyn F. Flores, K. Y. Tucto, Rolf Grieseler, Jorge A. Guerra, Jan A. Töfflinger, Andres Osvet, Miroslaw Batentschuk, Albrecht Winnacker, Roland Weingärtner, "Study of Near Infrared Photoluminescence in Yb³⁺, Er³⁺ and Yb³⁺, Tb³⁺ co-doped Silicon Oxycarbide Thin Films", talk.

· SPES 2018 (XXV Simposio Peruano de Energía Solar y del Ambiente), Cajamarca, Perú:

J. A. Töfflinger, R. Grieseler, A. Guerra, "Actividades en la Energías Renovables en la PUCP - Tecnologías fotovoltaicas emergentes: desde el material hasta la celda", invited talk. Presentation

· JOPES 2018 (Jornadas Peruanas de Energía Solar), Lima, Perú:

S. Gómez, E. Muñoz, J. Angulo, J. A. Guerra, J. de la Casa, A. Töfflinger: "Prediction of the energy produced by a photovoltaic system using a method proposed to obtain the maximum power under standard test conditions", poster. pdf

· SPES 2017 (XXIV Simposio Peruano de Energía Solar y del Ambiente), Huaraz, Perú:

L. A. Conde, A. Töfflinger, J. de la Casa, J. Angulo, S. Gomez: "Caracterización de paneles solares a sol real", talk. pdf

· SOPERFI´2017 (Sociedad Peruana de Física), Lima, Perú:

E. S. Serquen, L. F. Flores, R. Grieseler, J. A. Guerra, R. Weingärtner: “Efectos del recocido térmico en la composición y las propiedades ópticas de películas delgadas de oxicarburo de silicio”, talk.

· E-MRS 2017 (European Materials Research Society - Spring Meeting), Strasbourg, France:

L. F. Flores Escalante, K. Y. Tucto Salinas, J. A. Guerra Torres, A. Töfflinger, R. Weingärtner : “Fabrication and Luminescence Properties in Rare Earth Doped a-SiCxOy Thin Films”, talk.

· B-MRS 2017 (XVI Brazil Materials Research Society Meeting), Gramado, Brazil:

L. F. Flores Escalante, K. Y. Tucto Salinas, J. A. Guerra Torres, M. Batentschuk, A. Osvet, R. Grieseler, A. Töfflinger, R. Weingärtner : "Effect of thermal annealing on the luminescence properties of rare earth (Yb-Tb) co-doped silicon oxycarbide thin films”, talk.

· PRE’17 (International Workshops on Photoluminescence of Rare-Earth: Photonic Materials and Applications), Rome, Italy:

L. F. Flores Escalante, K. Y. Tucto Salinas, J. A. Guerra Torres, M. Batentschuk, A. Osvet, R. Grieseler, and R. Weingärtner : “Luminescence properties of rare earth (Yb–Tb) co-doped a-SiCxOy thin films”, talk.

· B-MRS 2017 (XVI Brazil Materials Research Society Meeting), Gramado, Brazil:

K. Tucto, L. Flores, J. Guerra, J. Töfflinger, J. Dulanto, R. Grieseler, A. Osvet, M. Batentschuk, R. Weingärtner: "Thermally activated luminescence in AlON:Tb3+:Yb3+ thin films for third generation photovoltaic solar cells", poster

· ICL 2017 (International Conference on Luminescence), Joao Pessoa, Brazil:

K. Tucto, L. Flores, J. Guerra, J. Töfflinger, J. Dulanto, R. Grieseler, A. Osvet, M. Batentschuk, R. Weingärtner: "Thermally activated luminescence in AlON:Tb3+:Yb3+ thin films for third generation photovoltaic solar cells", talk

· MRS 2017 (Material Research Society - Spring Meeting 2017), Phoenix, Arizona:

K. Tucto, L. Flores, J. Guerra, J. Töfflinger, J. Dulanto, R. Grieseler, A. Osvet, M. Batentschuk, R. Weingärtner: "Production and Characterization of Tb3+/Yb3+ Co-Activated AlON and AlN Thin Films for Down Conversion Applications in Photovoltaic Cells", poster.

· SINAPSIS 2017 (Meeting of Peruvian Scientists in Europe), Berlin, Germany:

J. Dulanto, K. Tucto, L. Florez, J. A. Guerra, J. A. Töfflinger, R. Grieseler and R. Weingärtner: “Hydrogenated Aluminum Nitride passivation layer doped with Terbium and Ytterbium rare earths for Photovoltaic Applications”, poster

· ICMSET 2016 (5th International Conference on Material Science and Engineering Technology), Tokyo, Japan:

K. Tucto, L. Flores, J. A. Guerra, R. Grieseler, T. Kups, J. Pezoldt, A. Osvet, M. Batentschuk and R. Weingärtner: "Extraction of radiative lifetime from emission spectra of terbium-doped AlN thin films using Judd-Ofelt analysis: Developing a new method", talk.

· ICMSET 2016 (5th International Conference on Material Science and Engineering Technology), Tokyo, Japan:

K. Tucto, L. Flores, J. A. Guerra, R. Grieseler, T. Kups, A. Osvet, M. Batentschuk and R. Weingärtner: "Effect of post-annealing treatments on the structure and luminescence properties of AlN:Tb3+ thin films prepared by radio frequency magnetron sputtering", talk.

· E-MRS 2016 (European Materials Research Society - Fall Meeting), Warsaw, Poland:

L. F. Flores, J. A. Guerra, R. Weingärtner: “Optical characterization of amorphous Ba-Fe-O thin films and their Fe-O glass network complexes”, talk.

· SOPERFI 2016 (Simposio Peruano de Física), Lima, Perú:

J. Dulanto, A. Tejada, J. A. Töfflinger, J. A. Guerra and R. Weingärtner: “Pasivación de obleas de silicio cristalino con películas delgadas de nitruro de aluminio (AlN) para aplicaciones fotovoltaicas”, talk.

· B-MRS 2015 (XIV Brazil Materials Research Society Meeting), Rio de Janeiro, Brazil:

J. A. Guerra, L. Montañez, A. Winnacker and R. Weingärtner: “Light emission characterization of Tb3+ doped a- SiC:H thin films”, talk.

J. A. Guerra, L. Montañez, J. Angulo, A. Winnacker and R. Weingärtner: “The Urbach Focus and optical properties of a- SiC:Hx”, poster.

· EMC 2015 (57th Electronic Materials Conference), Columbus-Ohio, USA:

J. A. Guerra, L. Montañez, A. Winnacker and R. Weingärtner: “Effect of thermal annealing treatments on the optical properties of Tb3+

doped amorphous SiC:H films”, poster.

· SOPERFI´2015 (Sociedad Peruana de Física), Lima, Perú:

A. Tejada, J. A. Guerra, R. Weingärtner: “Pulverización catódica con magnetrón RF: ventajas, desventajas y diseño", poster, pdf (396 kB).

· EDS2014 (17th International Conference on Extended Defects in Semiconductors), Göttingen, Germany:

J. A. Guerra, L. Montañez, A. Winnacker, F. De Zela and R. Weingärtner: “Thermal activation and temperature dependent PL and CL of Tb doped

amorphous AlN and SiN thin films”, poster.

· IMRC2014 (XXIII International Materials Research Congress 2014), Mexico, Cancun:

J. A. Guerra, L. Montañez, K. Tucto, A. Winnacker, F. De Zela and R. Weingärtner: “Thermal activation of terbium doped amorphous SiC:H thin films”, talk.

K. Tucto, J. A. Guerra, L. Montañez, A. Winnacker, F. De Zela and R. Weingärtner: “Determination of the Judd-Ofelt parameters of Tb doped SiC:H upon CL spectra”, talk.

· RIAO-OPTILAS´2013 (XVIII Iberoamerican Conference on Optics, XI Latinamerican meeting on Optics, Lasers and Applications), Porto, Portugal:

L. M. Montañez, J. A. Guerra, K. Zegarra, S. Kreppel, F. De Zela, A. Winnacker, and R. Weingärtner: “Optical bandgap enhancement of a-SiC through

hydrogen incorporation and thermal annealing treatments”, poster.

K. Zegarra, M. Merino, L. Montañez, J. A. Guerra, F. De Zela, A. Winnacker, and R. Weingärtner: “Optical and vibrational characterization of thin amorphous SiN films prepared by radio frequency magnetron sputtering”, talk.

· MRS´2013 (Materials Research Society), San Francisco, USA:

J. A. Guerra, F. Benz, L. Montañez, R. Grieseler, P. Schaaf, F. De Zela, A. Winnacker, H. P. Strunk, and R. Weingärtner: “Concentration Quenching of Tb³⁺ Doped SiC:H and AlN Thin Films in Photoluminescence and Cathodoluminescence Measurements”, talk.

J. A. Guerra, L. Montañez, F. De Zela, A. Winnacker, and R. Weingärtner: “On the origin of the Urbach rule and the Urbach focus”, poster, pdf (966 kB).

· EDS´2012 (International Conference on Extended Defects in Semiconductors), Thessaloniki, Greece:

J. A. Guerra Torres, F. Benz, A. R. Zanatta, A. Winnacker, H. P. Strunk, R. Weingärtner: “Concentration quenching of the luminescence from Terbium-doped c AlN and a-SiC:H thin films.”, poster, pdf (698 kB)

F. Benz, J. A. Guerra Torres, R. Weingärtner, H. P. Strunk: “How to describe concentration quenching in rare earth doped semiconductors.”, poster.

· IMRC´2012 (International Material ResearchConference), Cancún, Mexico:

L. Montañez, J. A. Guerra, S. Kreppel, F. De Zela, A. Winnacker, R. Weingärtner: “The effect of the annealing temperature on optical and vibrational properties of a-SiC and a-SiC:H.”, talk.

· SOPERFI´2011 (Sociedad Peruana de Física), Lima, Perú:

J. A. Guerra, K. Tucto, R. Weingärtner: “Determinación de las constantes ópticas y el espesor de películas delgadas dieléctricas: Una mejora del método de la envolvente y un análisis de confianza.”, talk.

· RIAO-OPTILAS´2010 (XVII Iberoamerican Conference on Optics, X Latinamerican meeting on Optics, Lasers and Applications), Lima, Perú:

J. A. Guerra, L. Montañez, O. Erlenbach, G. Galvez, F. De Zela, A. Winnacker, R. Weingärtner: “Optical constants determination of amorphous AlN and SiC thin films by single spectroscopic transmission measurements.”, talk.

G. Gálvez de la Puente, S. Zitzlsberger, J. A. Guerra Torres, O. Erlenbach, R. Weingärtner, F. De Zela, A. Winnacker: “Emission pattern of an aluminium nitride target for radio frequency magnetron sputtering.”, poster.

· IMRC´2009 (International Materials Research Conference), Cancún, Mexico:

G. Gálvez de la Puente, J. A. Guerra Torres, M. Steidl, O. Erlenbach, R. Weingärtner, F. De Zela, A. Winnacker: „Determination of the Emission Pattern of a Silicon Carbide Target for Radio Frequency Magnetron Sputtering.“, poster.

R. Weingärtner: “Bandgap Engineering of the Amorphous Wide Band-Gap Semiconductor (SiC)_1‑x(AlN)_x Doped with Rare Earths and its Optical Emission Properties.”, invited talk.

· ICSCRM´2009 (International Conference on Silicon Carbide and Related Materials), Nürnberg, Germany:

O. Erlenbach, G. Gálvez, J. A. Guerra Torres, F. De Zela, R. Weingärtner, A. Winnacker: „Thermal activation and cathodoluminescence measurements of Tb³⁺-doped a-(SiC)_1-x(AlN)_x thin films prepared by rf magnetron sputtering.”, poster.

G. Gálvez de la Puente, O. Erlenbach, T. Hupfer, M. Steidl, J. A. Guerra Torres, F. De Zela, R. Weingärtner, A. Winnacker: “Quality control and electrical properties of thin amorphous (SiC)_1‑x(AlN)_x films produced by radio frequency dual magnetron sputtering.”, poster.

J. A. Guerra Torres, A. Winterstein, M. Steidl, O. Erlenbach, G. Gálvez de la Puente, F. De Zela, R. Weingärtner, A. Winnacker: “Determination of the optical bandgap of thin amorphous (SiC)_1-x(AlN)_x films produced by radio frequency dual magnetron sputtering.”, poster.

· SOPERFI´2008 (Sociedad Peruana de Física) in Lima, Peru:

R. Weingärtner: „Preparación y Caracterización de Películas Delgadas de Compuestos pseudobinarios a-(SiC)_x(AlN)_1-x Dopadas con Tierras Raras Usando RF-Magnetron Sputtering.”, invited talk.