Hostname: page-component-788cddb947-kc5xb Total loading time: 0 Render date: 2024-10-12T14:03:55.799Z Has data issue: false hasContentIssue false

Hg1-xCdxTe as the Bottom Cell Material in Tandem II-VI Solar Cells

Published online by Cambridge University Press:  01 February 2011

Viral Parikh
Affiliation:
vparikh@physics.utoledo.edu, Wright Center for Photovoltaic Innovation and Commercialization, Physics and Astronomy, University of Toledo, 2801 W. Bancroft Street, Mail Stop #111, Toledo, OH, 43606, United States
Jie Chen
Affiliation:
Jie.Chen@utoledo.edu, Wright Center for Photovoltaic Innovation and Commercialization, Physics and Astronomy, University of Toledo, 2801 W. Bancroft Street, Mail Stop #111, Toledo, OH, 43606, United States
Sylvain Marsillac
Affiliation:
Sylvain.Marsillac@utoledo.edu, Wright Center for Photovoltaic Innovation and Commercialization, Physics and Astronomy, University of Toledo, 2801 W. Bancroft Street, Mail Stop #111, Toledo, OH, 43606, United States
Robert W Collins
Affiliation:
Robert.collins@utoledo.edu, Wright Center for Photovoltaic Innovation and Commercialization, Physics and Astronomy, University of Toledo, 2801 W. Bancroft Street, Mail Stop #111, Toledo, OH, 43606, United States
Alvin D Compaan
Affiliation:
Alvin.Compaan@utoledo.edu, Wright Center for Photovoltaic Innovation and Commercialization, Physics and Astronomy, University of Toledo, 2801 W. Bancroft Street, Mail Stop #111, Toledo, OH, 43606, United States
Get access

Abstract

We have measured the electrical, optical and morphological properties of as-grown Hg1-xCdxTe films prepared by r.f. sputtering. The Hg1-xCdxTe films were grown at substrate temperatures ranging from 25°C to 150°C. Films grown at temperatures lower than or equal to 70°C were highly resistive (≥105 Φ-cm) and were not measurable by our Hall apparatus. Optical transmission data show that the band gap of these films ranged from 0.8 eV-1.5 eV, satisfying the optimum band gap criteria. Plan view and cross sectional SEM studies indicate that the films grown at 85°C and 100°C have larger grains with compact grain boundaries and these films typically yield the best cell performance. Spectroscopic ellipsometry studies are being used to estimate the band-gap as a function of substrate temperature.

We have also studied the effect of various back contacts and have fabricated complete solar cells. We found that Cu-Au serves as the best ohmic back contact to CdS/HgCdTe solar cell. Our preliminary results of J-V analyses on the complete solar cell show that the efficiency is mainly limited by the short-circuit current. Electrical-bias-dependent QE measurements indicate voltage-dependent current collection mainly in the long wavelength region. Further optimization of growth parameters and CdCl2 treatment needs to be carried out to improve the cell performance.

Type
Research Article
Copyright
Copyright © Materials Research Society 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Coutts, T.J., Ward, J. Scott, Young, David L., Emery, Keith A., Gessert, Timothy A. and Noufi, Rommel, Prog. Photovolt: Res. Appl. 11, 359375 (2003).Google Scholar
2. Nemirowsky, Y., Finkmann, E., Journal of Applied Physics 50, 8107 (1979).Google Scholar