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

fYear

1996

fDate

13-17 May 1996

Firstpage

773

Lastpage

776

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 CdTe_1-xS_x 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 CdTe_1-xS_x with x near the solubility limit before heat treatment. An efficiency of 10.8% was achieved by a CdTe_1-xS_x/CdS device. The V_oc, J_sc, 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;

fLanguage

English

Publisher

ieee

Conference_Titel

Photovoltaic Specialists Conference, 1996., Conference Record of the Twenty Fifth IEEE

Conference_Location

Washington, DC

ISSN

0160-8371

Print_ISBN

0-7803-3166-4

Type

conf

DOI

10.1109/PVSC.1996.564242

Filename

564242