Title :
Polycrystalline CdTe on CuInSe2 cascaded solar cells
Author :
Meyers, P.V. ; Liu, C.H. ; Russell, L. ; Ramanathan, V. ; Birkmire, R.W. ; McCandless, B.E. ; Phillips, J.E.
Author_Institution :
Ametek Appl. Mater. Lab., Harleysville, PA, USA
Abstract :
Experimental results obtained using a CdS/CdTe/ZnTe top cell on a CdS/CuInSe2 bottom cell are presented. Single cells of each type exhibit an 11% efficiency. The fabrication of a mechanically stacked CdTe-CuInSe2 tandem cell that shows an efficiency of 9.9% is discussed. The current of the CuInSe2 cell is limited by the transmission through the CdTe cell. Semiquantitative analysis of the optical losses in the structure indicates that substantial improvements in tandem device performance can be achieved by: reducing free carrier absorption in the transparent (SnOx) top contact, e.g. by using an alternative transparent contact such as ITO or ZnO which has better near-IR transmission, and reducing the absorption in the Cu-doped ZnTe layer-perhaps by reducing the Cu doping level.
Keywords :
II-VI semiconductors; cadmium compounds; copper compounds; indium compounds; optical losses; solar cells; ternary semiconductors; 11 percent; 9.9 percent; CdS-CdTe-ZnTe-CdS-CuInSe2; CdS/CdTe/ZnTe top cell; CdS/CuInSe2 bottom; CdTe-CuInSe2 cascaded solar cell; fabrication; free carrier absorption reduction; near-IR transmission; optical losses; polycrystalline solar cell; semiconductor; transparent contact; Absorption; Indium tin oxide; Optical device fabrication; Optical devices; Optical losses; Performance analysis; Performance loss; Propagation losses; Zinc compounds; Zinc oxide;
Conference_Titel :
Photovoltaic Specialists Conference, 1988., Conference Record of the Twentieth IEEE
Conference_Location :
Las Vegas, NV, USA
DOI :
10.1109/PVSC.1988.105949
