Abstract
The recent literature regarding the stability of CdTe/CdS photovoltaic cells (as distinguished from modules) is reviewed. Particular emphasis is given to the role of Cu as a major factor that can limit the stability of these devices. Cu is often added to improve the ohmic contact to p-CdTe and the overall cell photovoltaic performance. This may be due to the formation of a Cu2Te/CdTe back contact. Excess Cu also enhances the instability of devices when under stress. The Cu, as Cu+, from either Cu2Te or other sources, diffuses via grain boundaries to the CdTe/CdS active junction. Recent experimental data indicate that Cu, Cl and other diffusing species reach (and accumulate at) the CdS layer, which may not be expected on the basis of bulk diffusion. These observations may be factors in cell behavior and degradation, for which new mechanisms are suggested and areas for future study are highlighted. Other possible Cu-related degradation mechanisms, as well as some non-Cu-related issues for cell stability are discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 295-325 |
| Number of pages | 31 |
| Journal | Solar Energy Materials and Solar Cells |
| Volume | 62 |
| Issue number | 3 |
| DOIs | |
| State | Published - 15 May 2000 |
| Externally published | Yes |
Funding
This research was supported through the United States DOE, via the National Renewable Energy Laboratories’ Thin-Film Photovoltaics Partnership Program. The authors thank K. Zweibel and D. Albin of NREL, A. Compaan and D. Grecu of the University of Toledo, J. Sites of Colorado State University and B. McCandless, S. Hegedus and R. Birkmire of University of Delaware, for their assistance and advice, and K. Gartsman (Weizmann Institute) for discussions.
| Funders | Funder number |
|---|---|
| U.S. Department of Energy | |
| National Renewable Energy Laboratory |
