Cu_xS back contact for CdTe solar cells

Donghwan Kim*, B.E. McCandless, S.S. Hegedus, and R.W. Birkmire

Institute of Energy Conversion, University of Delaware, Newark, Delaware 19716, U.S.A.

* On leave from Korea University, Seoul, Korea.

Recibido el 9 de junio de 2006
Aceptado el 26 de octubre de 2006

Abstract

Copper sulfide (Cu_xS) films were studied as a back contact material for CdTe solar cells. The Cu_xS films were made by chemical bath deposition in aqueous solution. Annealing at 200°C in Ar improved the performance of the solar cells. Using the CdS/CdTe/Cu_xS/C structure, an open–circuit voltage (V_oc) higher than 840 mV and an energy conversion efficiency higher than 11% were obtained.

Keywords: Copper sulfide; cadmium telluride; solar cells; contact resistance.

Resumen

Se estudiaron películas de sulfuro de cobre (CuxS) como material de contacto posterior para células solares de CdTe. Las películas de CuxS se hicieron por deposición en baño químico de solución acuosa. El recocido a 200°C en Ar mejoró el rendimiento de las células solares. Mediante la estructura CdS/CdTe/CuxS/C, se obtuvo un voltaje de circuito abierto (VCA) superior a los 840 mV y una eficacia de conversin de energía superior al 11%.

Descriptores: Sulfito de cobre; telurio de cadmio; celdas solares; resistencia de contacto.

PACS: 84.60.Jt; 73.40.Cg

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Acknowledgments

The authors wish to thank First Solar, Inc. for the CdTe samples. One of the authors (Donghwan Kim) was partially supported by the Korea Ministry of Commerce, Industry and Energy through the academic promotion program of the Korea Energy Management Corporation (KEMCO).

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