Three types of characteristic behavior of photoluminescence (PL) intensity response were found for InP crystal surfaces according to various surface preparations and measuring ambients. Gradual increase of photoluminescence intensity with time occurs on the surface etched by methanol-Br2 etching solution and in all the examined ambients: N2, H2, Ar, O2, air, and vacuum (6×10-3 Torr). A gradual decrease appears on the surface treated by HNO3, HF, HCl, and H 3PO4 and in the O2-containing ambients. These tendencies can be repeated reversibly by treating the surface using each method. Influence of the crystal orientation and conduction type on these phenomena was investigated. PL intensity from the surface treated by AgNO3 and CuSO4 solution is fixed at a low level irreversibly.
