Shallow donor state removal via photoelectrochemical etching in Cd(Se,Te)

Abstract Low temperature photoluminescence (PL) measurements together with transport measurements, scanning electron microscopy (SEM), and proton induced X-ray emission (PIXE), were carried-out for undoped and In-doped n-type CdSe 0.54 Te 0.46 . SEM analysis of PE surfaces showed a dense pattern of etch pits. The present results show that PE selectively removes shallow donors from the semiconductor surface. To explain these and other results, a model is proposed suggesting that photocurrents, generated by short wavelength excitation at semiconductor junctions, are non-uniform and are influenced by the presence of microscopic electric fields induced by the ionized impurities near the semiconductor surface.