Polishing Damage and Luminescence in p‐Type GaAs

The photoluminescence of zinc‐doped GaAs has been studied for different surface preparations. Mechanically polished specimens fluoresced less than chemically prepared ones. Etch‐pit studies using a dislocation etch indicated that mechanical polishing introduced dislocations and samples showing the largest number of etch pits showed the weakest photoluminescence. It was also shown that diffusing a large concentration of zinc into n‐type GaAs introduces dislocations, and it is suggested that this is the reason for the low photoluminescence efficiency of zinc‐doped GaAs for concentrations in excess of 1019 cm−3.