Optimization of Layer Properties for High Efficiency CdTe solar cell with Higher Band Gap CdMgTe Layer as Back Electron Reflector

ORAL

Abstract

Thin film CdTe solar cell has been an option for PV energy solution with a potential of massive terrestrial installation. The open circuit voltage of traditional CdTe cell (up to 0.85V) has been the biggest limit to higher cell efficiency. Adding an additional layer of CdMgTe as back electron reflector with fitted band alignment to CdTe has been proposed to increase Voc by as high as the conduction band energy offset (CBO). Further increase from the same approach may cause tradeoff of fill factor and Jsc. Study of band structure, dark and light J-V curves, quantum efficiency spectrum has been carried out by applying a1-D numerical simulation program. Layer properties are optimized considering experimental facts for charge generation, separation and collection. Primary experimental results have demonstrated the prediction on cell degradation caused by valence band barrier between CdTe and CdMgTe. Solutions have been proposed for further improvements.

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Authors

  • Jinming Zhang

    Colorado State University

  • Benjamin Bloom

    Department of Physics, University of Arizona, Tucson, AZ, National Institute for Materials Science, Tsukuba, Japan, The University of Electro-Communications, Tokyo, Langmuir Laboratory, New Mexico Tech, The University of Arizona, Brigham Young University, Department of Physics Colorado State University, Colorado School of Mines, National Renewable Energy Laboratory, University of Colorado Boulder, Principal Investigator, Graduate Student, Colorado State University, SSRL, SLAC, Department of Chemistry and Biochemistry, Brigham Young University, Department of Physics and Astronomy, Brigham Young University, National Tsing Hua University, Hsinchu, Taiwan, Colorado State Univ, JILA, University of Colorado at Boulder, NIST, JILA, University of Colorado at Boulder, Heinrich-Heine-Universitat, Department of Physics, University of Colorado Denver, Denver, CO 80217, Biomedical Engineering, University of Texas at Austin, Austin, TX, The University Centre in Svalbard, Utah State University, Utah Valley University, New Mexico State University, The George Washington University Nuclear Physics Research Group, Institute for Nuclear Physics at the Johannes Gutenberg University of Mainz, None, Colorado State Engineering Research Center, St. Petersburg Electrotechnical University in Saint Petersburg, Russia, University of California San Diego, Argonne National Laboratory, Los Alamos National Laboratory, Imperial College London, Space Dynamics Lab, Utah State University, Physics and CASS, Utah State University, Department of Chemistry, Colorado State University, Fort Collins, CO 80523, Department of Physics, Colorado State University, Fort Collins, CO 80523, Dept. of Electrical, Computer, and Energy Engineering, University of Colorado at Boulder, Dept. of Physics and Astronomy, University of Denver, CU Boulder, RASEI, NREL, University of Colorado, Rutgers, UTK, Joint Institute for Heavy Ion Research \& ORNL, University of Guelph, Insitituto de Estructura de la Materia, University of Toronto, INFN Laboratori Nazionali del Sud, University of York, University of Surrey, TRIUMF, Simon Frasier University, Universdad de Sevilla, Simon Fraser University, Univ of Utah, Univ of Wyoming, New Mexico Tech, GLOBALFOUNDRIES, IBM Systems and Technology Group, IBM Research Division, Irvine Valley College, University of Colorado - Boulder, Department of Physics, Arizona State University, Tempe, AZ, Department of Physics, New Mexico State University, Las Cruces, NM, Department of Physics, University of Michigan, Flint, MI, High Altitude Observatory, JILA, University of Colorado