High-rate vapor deposition of cadmium telluride films for solar cells

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:5902119

Khan, N A

High rate vapor deposition is presently used for large scale low cost deposition of thin films for packaging and other applications. The feasibility of using this technology for low cost deposition of solar cells was explored. After an exhaustive literature survey, the cadmium telluride (CdTe) solar cell was found to be most suitable candidate for high rate vapor deposition. The high rate vapor deposition was investigated by sublimation with a short distance between sublimation source and the substrate (Close-Spaced Sublimation, CSS). Cadmium telluride (CdTe) solar cells were fabricated by depositing CdTe films at different rates on cadmium sulphide (CdS) films deposited by CSS or by evaporation. The CdTe films deposited at higher deposition rates were observed to have open circuit voltages (V[sub oc]) comparable to those deposited at lower rates. The effect of CdS film which acts as window layer for the cells were also investigated on the V[sub oc] of the solar cells. The results achieved proved the fact that CdS window layer is necessary to achieve higher V[sub oc] from solar cells. The increase in the substrate temperature during deposition of CdTe films increased the V[sub oc] from solar cells. The substrate temperature during deposition of films by close space sublimation plays a vital role in the performance of solar cell. The increase in the substrate temperature during deposition of CdTe films increased the V[sub oc] of solar cells. The solar cells with indium tin oxide (ITO) as top conductor, i.e. ITO/CdS/CdTe configuration, fabricated at rates up to 34 [mu]m/minute and with tin oxide (TO) i.e. TO/CdTe configuration, fabricated at rates up to 79 [mu]m/minute, have shown similar V[sub oc] compared to those produced at lower rates. The method of contacting CdTe, used in this study, results in higher series resistance. An improved method of contacting CdTe needs to be developed.

• Research Organization: Colorado State Univ., Fort Collins, CO (United States)
• OSTI ID: 5902119
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
CADMIUM COMPOUNDS
CADMIUM SULFIDES
CADMIUM TELLURIDE SOLAR CELLS
CHALCOGENIDES
DEPOSITION
DIRECT ENERGY CONVERTERS
EQUIPMENT
EVAPORATION
FILMS
INDIUM COMPOUNDS
INDIUM OXIDES
INORGANIC PHOSPHORS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHOSPHORS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL VAPOR DEPOSITION
SOLAR CELLS
SOLAR EQUIPMENT
SUBLIMATION
SUBSTRATES
SULFIDES
SULFUR COMPOUNDS
SURFACE COATING
SYNTHESIS
THIN FILMS
TIN COMPOUNDS
TIN OXIDES