Description: The objectives of this contract are to investigate thin films of cadmium telluride on low cost substrates and to demonstrate the feasibility of producing thin film cells with a conversion efficiency of 10% or higher. Efforts during the first quarter have been direcrted to the construction of apparatus for the chemical vapor deposition of cadmium telluride films, the selection and preparation of substrates, and the deposition and characterization of cadmium telluride films. Cadmium telluride films have been deposited on a number of substrates by the direct combination of cadmium and tellurium on the substrate surface at 550 to 740/sup 0/C. At substrate temperatures below 550/sup 0/C, the deposit is non-adherent. In the temperature range 580 to 740/sup 0/C, the deposition rate is 0.5 to 1 ..mu..m/min, and the microstructure and crystallographic properties of deposited films have been investigated. Without intentional doping, cadmium telluride films deposited on mullite substrates have room temperature resistivities and carrier concentrations of (4-7) x 10/sup 4/ ohm-cm and (6-9) x 10/sup 12/ cm/sup -3/, respectively. Current-voltage measurements of Schottky barriers prepared from cadmium telluride films indicate the rectifying interface in CdTe/W/graphite, CdTe/graphite, CdTe/Al/graphite structures and the presence of pinholes in the films.
Date: October 1, 1979
Creator: Chu, T. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department