Electrical properties of CdS/CdTe heterojunctions

Journal Article · Mon Aug 01 04:00:00 EDT 1988 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.341840· OSTI ID:7077873

Chu, T L; Chu, S S; Ang, S T

The electrical properties of n-CdS/p-CdTe heterojunctions depend strongly on the cleanliness of the interface region. In this work, CdTe films were deposited on CdS/glass substrates by close-spaced sublimation (CSS) under various conditions. The dark current-voltage characteristics of the resulting heterojunctions were measured over a wide temperature range, and the capacitance-voltage characteristics were measured in the dark and under illumination. When the CdS surface is in situ cleaned prior to the deposition of the CdTe film, the current transport across the junction is controlled by a thermally activated process. Tunneling makes an important contribution to the interface recombination at temperatures below room temperature when the in situ cleaning of CdS is not used. The dark capacitance of CdS/CdTe heterojunctions prepared with in situ etching is essentially independent of the reverse bias due to intrinsic interface states. Under white light illumination, the 1/C /sup 2/ vs V relation is nearly linear. The CdS/CdTe heterojunctions without in situ cleaning showed different 1/C /sup 2/ vs V relations due to higher density of interface states. The in situ cleaning also has pronounced effects on the frequency dependence of dark and illuminated capacitances. Using the in situ cleaning technique, solar cells of about 1 cm/sup 2/ area have achieved an AM 1.5 (global) efficiency of about 10.5%.

• Research Organization: Southern Methodist University, Dallas, Texas 75275
• OSTI ID: 7077873
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 64:3; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
CADMIUM COMPOUNDS
CADMIUM SULFIDES
CADMIUM TELLURIDES
CAPACITANCE
CHALCOGENIDES
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
DEPOSITION
DIRECT ENERGY CONVERTERS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EQUIPMENT
FABRICATION
FILMS
HETEROJUNCTIONS
INORGANIC PHOSPHORS
JUNCTIONS
MATERIALS
MEDIUM TEMPERATURE
N-TYPE CONDUCTORS
P-TYPE CONDUCTORS
PHOSPHORS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
SEMICONDUCTOR JUNCTIONS
SEMICONDUCTOR MATERIALS
SOLAR CELLS
SOLAR EQUIPMENT
SULFIDES
SULFUR COMPOUNDS
SURFACE COATING
TELLURIDES
TELLURIUM COMPOUNDS
TEMPERATURE DEPENDENCE