Formation of p/sup +/ CdTe contact with Cu/sub 2/Te electrode and its stability in CdTe cells

Cu/sub 2/Te electrode was utilized as a Cu source to form p/sup +/-CdTe and its stability in CdTe cells has been investigated. An amorphous interlayer was found at the CdTe/Cu/sub 2/Te interface by depositing Cu/sub 2/Te at room temperature and it was crystallized by annealing at 200/spl deg/C, enhancing the growth of hexagonal phase compared to orthorhombic phase. A good p/sup +/ ohmic contact was formed at 180/spl deg/C annealing and the best efficiency was obtained at 200/spl deg/C. The cell efficiency was degraded under forward bias and it was either improved or recovered both under reverse bias and by additional annealing, The cell with thinner CdTe layer was degraded faster and more severely affected by bias stress.