Deep level characterization of seeded physical vapor transport grown ZnSe

Abstract

Deep level characterization of ZnSe grown using the seeded physical vapor transport (SPVT) technique is presented for the first time. Deep level characterization of ZnSe grown by the high pressure Bridgman technique is also presented primarily for the purpose of comparison. Thermally stimulated current (TSC) measurements reveal several hole trapping levels in the SPVT samples. TSC from the Bridgman samples, however, reveals a complex structure of overlapping peaks which we were unable to resolve. Thermoluminescence (TL) measurements on Bridgman samples indicate that the primary radiative recombination center is the Cured center (Ev + 0.71 eV). No TL was observed from the SPVT samples despite the fact that TSC and photoluminescence (PL) reveal the presence of both the Cured and Cugreen (Ev + 0.33 eV) centers in both types of sample. We present a model which describes the role of these centers in both SPVT and Bridgman samples and which explains the lack of TL from the SPVT specimens.

Dose Dependences of the Conductivity and Luminescence in ZnSe Single Crystals

“…The accumulation of charge carriers during crystals excitation occurs only in the phosphorescent and deep traps. It is known that in the low-temperature region (up to 300 K), we observe TSL in ZnSe crystals [17,18]. Above room temperature, there are deep traps in the ZnSe crystals, as evidenced by the curve 1 in Fig.…”