SPECTROSCOPIC ELLIPSOMETRIC STUDY OF ZN1-XMNXTE FILMS GROWN ON GAAS

We present the first spectroscopic ellipsometric study of Zn1-xMnxTe f ilms (0 less than or equal to x less than or equal to 1) grown on GaAs substrates. We report a chemical etching procedure that yield a ZnTe pseudodielectric spectrum with the least influence so far from surface overlayers. We found that the room-temperature E-0 band gap increases with Mn concentration, while the E-1 and E-2 band gaps decrease. The decrease of the E-1 band gap is due to the hybridization of Mn 3d elec trons with ZnTe band electrons. In contrast to results obtained with m ost other nonmagnetic alloys, the linewidths of the band gap structure s increase monotonically with x, showing broad amorphous-like dielectr ic behavior at the MnTe endpoint.