PREPARATION AND OPTICAL-PROPERTIES OF WIDE GAP II-VI COMPOUNDS

Large gap II-VI semiconductors have direct band gaps with gap energies ranging from 3.84 (ZnS) to 1.44 eV (CdTe) at RT. They promise optoelectronic devices operating in the visible spectral range. However, a large number of defects and difficulties in preparing n- and p-type material have hampered a broad application. New epitaxial growth methods such as MOVPE and MBE offer a chance to overcome many of these problems and even make a controlled doping possible. The present paper summarizes some aspects of the recent development for ZnS, ZnSe, ZnTe and a few ternary compounds.