Optoelectronic Properties and Charge Carrier Dynamics of Polycrystalline ZnTe Thin Films
Yuke Zhao1,2, Zhenglin Jia1,2, Qianqian Lin1,2,3,4
1Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education of China, School of Physics and Technology, Wuhan University, Wuhan 430072, China.
Abstract:
ZnTe is a wide-bandgap semiconductor with great potential for optoelectronic applications. The performance of ZnTe-based devices is strongly influenced by the dynamics of photogenerated carriers in polycrystalline films. In this work, we investigate the charge carrier dynamics in thermally evaporated polycrystalline ZnTe films under various pump intensities using transient absorption spectroscopy. We observe an inverse relationship between the pump intensity and free carrier lifetime. It is found that this anomalous behavior is attributed to the rapid trapping of free carriers by defects. Furthermore, by comparison of temperature-dependent TA spectra and steady-state absorption spectra, the temperature-dependent charge carrier dynamics and excitonic absorption have been evaluated.
