Polycrystalline thin film materials and devices
Abstract
Phase 2 results of a research program on polycrystalline thin film heterojunction solar cells are presented. Relations between processing, materials properties, and device performance were studied. The analysis of these solar cells explains how minority carrier recombination at the interface and at grain boundaries can be reduced by doping of windows and absorber layers, such as in high efficiency CdTe and CuInSe2 based solar cells. The additional geometric dimension introduced by the polycrystallinity must be taken into consideration. The solar cells are limited by the diode current, caused by recombination in the space charge region. J-V characteristics of CuInSe2/(CdZn)S cells were analyzed. Current-voltage and spectral response measurements were also made on high efficiency CdTe/CdS thin film solar cells prepared by vacuum evaporation. Cu-In bilayers were reacted with Se and H2Se gas to form CuInSe2 films; the reaction pathways and the precursor were studied. Several approaches to fabrication of these thin film solar cells in a superstrate configuration were explored. A self-consistent picture of the effects of processing on the evolution of CdTe cells was developed.
- Publication:
-
Unknown
- Pub Date:
- October 1992
- Bibcode:
- 1992ptfm.rept.....B
- Keywords:
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- Cadmium Sulfides;
- Cadmium Tellurides;
- Copper Selenides;
- Heterojunctions;
- Indium Compounds;
- Polycrystals;
- Selenides;
- Solar Cells;
- Thin Films;
- Zinc Sulfides;
- Electrical Properties;
- Photoelectric Effect;
- Solid-State Physics