Combined Optical-Electrical Optimization of Cd1-xZnxTe/Silicon Tandem Solar Cells

Mehmet Koç; Giray Kartopu; Selcuk Yerci

doi:10.3390/ma13081860

Combined Optical-Electrical Optimization of Cd_1-xZn_xTe/Silicon Tandem Solar Cells

Materials (Basel). 2020 Apr 15;13(8):1860. doi: 10.3390/ma13081860.

Authors

Mehmet Koç^{1

2}, Giray Kartopu³, Selcuk Yerci^{1

2

4}

Affiliations

¹ The Center for Solar Energy Research and Applications (GUNAM), Ankara 06800, Turkey.
² Micro and Nanotechnology Department, Middle East Technical University, Ankara 06800, Turkey.
³ Centre for Solar Energy Research, OpTIC, Swansea University, St. Asaph Business Park, Saint Asaph LL17 0JD, UK.
⁴ Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara 06800, Turkey.

Abstract

Although the fundamental limits have been established for the single junction solar cells, tandem configurations are one of the promising approaches to surpass these limits. One of the candidates for the top cell absorber is CdTe, as the CdTe photovoltaic technology has significant advantages: stability, high performance, and relatively inexpensive. In addition, it is possible to tune the CdTe bandgap by introducing, for example, Zn into the composition, forming Cd_1-xZn_xTe alloys, which can fulfill the Shockley-Queisser limit design criteria for tandem devices. The interdigitated back contact (IBC) silicon solar cells presented record high efficiencies recently, making them an attractive candidate for the rear cell. In this work, we present a combined optical and electrical optimization of Cd_1-xZn_xTe/IBC Si tandem configurations. Optical and electrical loss mechanisms are addressed, and individual layers are optimized. Alternative electron transport layers and transparent conductive electrodes are discussed for maximizing the top cell and tandem efficiency.

Keywords: CdTe; CdZnTe; IBC silicon cell; ZnTe; c-Si; photovoltaic cell; tandem cell.

Abstract

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