naa a22 4500 510804977 CHVBK 20180411083412.0 cr unu---uuuuu 180411e20131101xx s 000 0 eng 10.1007/s11664-013-2702-0 doi (NATIONALLICENCE)springer-10.1007/s11664-013-2702-0 Simulation of Current Transport in Polycrystalline CdTe Solar Cells [Elektronische Daten] [F. Troni, R. Menozzi, E. Colegrove, C. Buurma] Polycrystalline thin-film CdTe solar cells have demonstrated laboratory efficiency exceeding 17% and are nowadays a commercial technology (albeit with somewhat lower efficiencies). The standard process features a poorly understood recrystallization step, obtained by annealing with a source of chlorine. This study uses two-dimensional numerical modeling to investigate current transport inside the polycrystalline CdTe absorber with and without recrystallization effects [increase of grain size and donor ClTe states at grain boundaries (GBs)]. Solving the Poisson equation and the drift-diffusion model for transport with Fermi statistics, while treating the optical problem by the one-dimensional transfer matrix method and complex refractive indexes, this study shows that: (i) in a columnar absorber (i.e., one where only vertical GBs exist), the presence of ClTe donor traps at GBs results in a dip in the band profiles that effectively serves as an electron collector, significantly increasing the short-circuit current and efficiency compared with nondecorated GBs; (ii) while the same dip acts as a hole barrier and thus can be expected to block holes from flowing when horizontal GBs are present, under illuminated conditions electron collection at GBs reduces the dip enough to allow substantial hole flow, and the cell performance is only moderately affected. TMS, 2013 Photovoltaic nationallicence thin-film solar cells nationallicence CdTe nationallicence grain boundaries nationallicence numerical modeling nationallicence Troni F. Department of Information Engineering, University of Parma, 43124, Parma, Italy aut Menozzi R. Department of Information Engineering, University of Parma, 43124, Parma, Italy aut Colegrove E. Microphysics Laboratory, Department of Physics, University of Illinois at Chicago, 60607, Chicago, IL, USA aut Buurma C. Microphysics Laboratory, Department of Physics, University of Illinois at Chicago, 60607, Chicago, IL, USA aut Journal of Electronic Materials Springer US; http://www.springer-ny.com 42/11(2013-11-01), 3175-3180 0361-5235 42:11<3175 2013 42 11664 https://doi.org/10.1007/s11664-013-2702-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11664-013-2702-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Troni F. Department of Information Engineering, University of Parma, 43124, Parma, Italy aut NATIONALLICENCE 700 1- Menozzi R. Department of Information Engineering, University of Parma, 43124, Parma, Italy aut NATIONALLICENCE 700 1- Colegrove E. Microphysics Laboratory, Department of Physics, University of Illinois at Chicago, 60607, Chicago, IL, USA aut NATIONALLICENCE 700 1- Buurma C. Microphysics Laboratory, Department of Physics, University of Illinois at Chicago, 60607, Chicago, IL, USA aut NATIONALLICENCE 773 0- Journal of Electronic Materials Springer US; http://www.springer-ny.com 42/11(2013-11-01), 3175-3180 0361-5235 42:11<3175 2013 42 11664 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer