High voltage thermally diffused p/sup +/n solar cells

The possibility of fabricating thermally diffused p/sup +/n InP solar-cells with high open-circuit voltage without sacrificing the short circuit current is discussed. The p/sup +/n InP junctions were formed by Cd and Zn diffusion through a 3-5 nm thick anodic or chemical phosphorus-rich oxide cap layer grown on n:InP:S (with N/sub D/-N/sub A/=3.5*10/sup 16/ and 4.5*10/sup 17/ cm/sup -3/) Czochralski LEC-grown substrates. After thinning the emitter from its initial thickness of 1 to 2.5 mu m down to 0.06-0.15 mu m, the maximum efficiency was found when the emitter was 0.2 to 0.3 mu m thick. Typical AM0, 25 degrees C values of 854-860 mV were achieved for V/sub oc/, J/sub sc/ values were from 25.9 to 29.1 mA/cm/sup 2/ using only the P-rich passivating layer left after the thinning process as an antireflection coating.<
>