Title :
Thin film cadmium telluride-cadmium sulfide alloys and devices [solar cells]
Author :
Jensen, D.G. ; McCandless, B.E. ; Birkmire, R.W.
Author_Institution :
Inst. of Energy Conversion, Delaware Univ., Newark, DE, USA
Abstract :
The CdTe-CdS alloy system has been characterized at typical solar cell processing temperatures in order to elucidate the role of interdiffusion in CdTe/CdS-based solar cells. Predominately single-phase CdTe1-xSx thin films with x≡[S]/([S]+[Te]) ranging from 0 to 0.45, were grown by vacuum co-evaporation of CdS and CdTe. Phase segregation was promoted by heat treatment of the films at 415°C in the presence of CdCl2. The solubility limits of S in CdTe and Te in CdS at 415°C were derived by measuring the compositions of the two phases in the films after the CdCl2 treatment. The solubility limit of S in CdTe was determined to be 5.8%. Solar cells were fabricated with compositionally uniform absorber layers of CdTe1-xSx with x near the solubility limit before heat treatment. An efficiency of 10.8% was achieved by a CdTe1-xSx/CdS device. The Voc, Jsc , fill factor and spectral response of this device were all very similar to vacuum evaporated conventional CdTe/CdS cells where the alloy is formed by diffusion of S during cell processing
Keywords :
II-VI semiconductors; cadmium compounds; chemical interdiffusion; semiconductor device testing; semiconductor growth; semiconductor thin films; solar cells; vapour deposited coatings; vapour deposition; 10.8 percent; 415 C; CdTe-CdS; CdTe-CdS solar cells; fill factor; heat treatment; interdiffusion; open-circuit voltage; phase segregation; processing temperature; short-circuit current; solubility limits; spectral response; thin-film semiconductor; vacuum co-evaporation; Atomic measurements; Cadmium compounds; Glass; Optical films; Photonic band gap; Photovoltaic cells; Tellurium; Temperature; Thin film devices; Transistors;
Conference_Titel :
Photovoltaic Specialists Conference, 1996., Conference Record of the Twenty Fifth IEEE
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-3166-4
DOI :
10.1109/PVSC.1996.564242
