CdZnTe晶体位错处的Raman光谱及PL谱研究

Raman and Photoluminescence Study on Dislocations in CdZnTe Crystal

利用显微Raman光谱技术,对比研究了CdZnTe晶体无位错区和位错密集区的Raman光谱。研究发现,CdZnTe晶体无位错区的Raman光谱出现了与Te有关的A1模(119 cm-1)、类CdTe的TO1模(138 cm-1)和类ZnTe的TO2模(179 cm-1);CdZnTe晶体位错密集区的Raman光谱中仅出现了与Te有关的A1模和类CdTe的TO1模,CdZnTe晶体类ZnTe的TO2模消失。对CdZnTe试样位错密集区进行变温光致发光谱测试,结果表明,束缚在中性施主上的激子的离解为电子空穴对,电子空穴的非辐射复合过程吸收了类ZnTe的TO2模声子能量,造成Raman光谱中类ZnTe的TO2模缺失。

The Raman spectra were acquired in CdZnTe crystal in both dislocation free zone and dislocation densing region. With the spectra obtained in the dislocation free zone, the phonon peaks A1 （Te precipitates）, TO1 （CdTe-like）, TO2 （ZnTe-like） are seen. Raman spectra obtained in dislocation densing region are consistent with A1 and TO1 modes, but TO2 peak disappeared spectrum of CdZnTe crystal in dislocation densing region are investigated ~ Further photolumince by photoluminescence microscopy with temperature from 10 K to 150 K. The results showed that the nonradiative recombination of electron-hole pairs absorb the energy of TO2 phonon, causing the lack of TO2 peak in Raman spectra obtained in dislocation densing region.