FORMATION OF LOW-RESISTANCE CONTACTS TO P-CDTE BY ANNEALING AUTOCATALYTICALLY DEPOSITED NI-P ALLOY COATINGS

A novel technology for forming low resistance ohmic contacts to p-CdTe has been developed. The technology is based on the autocatalytic depo sition of NI-P alloy coatings onto p-CdTe followed by an anneal to red uce the degree of supersaturation of P in Ni and to hence diffuse P in to the CdTe. Energy dispersive X-ray analysis (EDAX) and X-ray diffrac tion data were used to monitor changes in the Ni-P during the annealin g and contact resistance measurements made to assess the viability of the technology. The data are consistent with the in-diffusion of P int o the CdTe and the specific contact resistivity reduced to 0.08-0.1 Om ega . cm(2) for an optimum annealing temperature of 250 degrees C. The contact technology has also been applied to the p-CdTe used in CdS/Cd Te thin film solar cells with encouraging results.