LARGE ACTIVATION OF PRASEODYMIUM IN IN0.53GA0.47AS

The electrical properties of Pr-doped In0.53Ga0.47As LPE epitaxial lay ers have been studied. Layers prepared by adding a small amount of PrO 2 to the melt are n-type and they are insensitive to the temperature t reatment. p-type epitaxial layers were grown when more than 1 mg of Pr O2 per 1 g of In was added to the melt. Annealing at a temperature of 400-degrees-C results in drastic changes of the electrical parameters and influences the photoluminescent spectra of p-layers. Praseodymium can be activated in a thin near-surface layer independently of the pro tective gas or metal covering. Additional annealing of the activated l ayers at higher temperatures has no further influence on the parameter s. After removing the thin surface layer by chemical etching the previ ous electrical parameters can be obtained.