A study of deep centers in Zn1−xMgxSe crystals using deep-level transient spectroscopy

Defects in Zn1−xMgxSe have been studied using deep-level transient spectroscopy. The crystalline material with low Mg concentration (x=0.09, 0.15), obtained by the high-pressure Bridgman method, has a sphalerite structure and shows n-type conductivity. A major electron trap was found with a thermal activation energy of 0.37 eV (x=0.09) and 0.38 eV (x=0.15), respectively. The trap concentration was 1.5–2.7×1014 cm−3. From capture measurements we obtained the electron capture rate cn as a function of the temperature, providing information about the thermal activation energy of the capture process. The capture barrier ΔEb splits into a high-temperature section with Eb=145 meV and a low-temperature section with a value of 66 meV for Eb. It is assumed that the predominant trap in Zn1−xMgxSe has the same origin as the well-known ∼0.32 eV trap in ZnSe.