Eun Kyo Byun1 Jongha Son1 Donghwan Kim2 Jihyun Kim1

1, Korea University, Seoul, , Korea (the Republic of)
2, Korea University, Seoul, , Korea (the Republic of)

As conventional solar cells use the incident light through only one side of the cell, it is important to arrange the solar cells toward the direction of the sunlight, which varies with time. Bifacial solar cells can use the incident light from both sides, which makes the cell efficiency less dependent on the angle of the incident light. Therefore, bifacial solar cells produce higher power per unit area than conventional monofacial solar cells. Among the various solar cells, thin-film solar cells have attracted attention due to their advantages of light weight and low manufacturing cost. One type of the thin-film solar cells, Cadmium Telluride (CdTe) thin-film solar cells, have been commercialized successfully and investigated with great interest owing to their high theoretical efficiency(~29%). However, only a few researches on the bifacial configuration of CdTe thin-film solar cells have been reported.
In this work, copper nanowires/indium tin oxide (CuNWs/ITO) are used as transparent back contact material. CuNWs have high optical transmittance and conductivity, which are essential properties for transparent back contact. In addition, Cu can act as a p-type dopant in CdTe. Therefore, CuNWs are expected to act as a dopant and enhance the contact properties with CdTe layer. CuNWs were spray-coated onto CdTe and followed by the ITO deposition. ITO improves the electrical properties of NWs network and protects the CuNWs from oxidation without significant loss of optical transmittance. Optical, electrical and photovoltaic properties of the CdTe thin-film solar cells with CuNWs/ITO back contact were investigated and high total efficiency of ~10% was obtained by optimizing the amount of CuNWs deposited. The details of our work will be presented in the meeting