以電漿輔助式分子束磊晶成長之氧化鎘鋅薄膜在熱效應下的載子遷移過程研究

Abstract

本研究以分子束磊晶成長氧化鎘鋅薄膜，利用光激螢光與時間解析光譜等技術來探討在溫度效應下氧化鎘鋅薄膜的載子躍遷行為。我們發現鎘摻進氧化鋅後會在能帶中產生深淺不一的侷限態，當溫度升高時載子受聲子散射的影響會從淺的侷限態躍遷至較深的侷限態發光，因此會造成螢光訊號隨著溫度會有劇烈的紅位移現象，從時間解析光譜中可以明顯觀察到當溫度升高時，載子隨著時間往低能量躍遷的現象，為載子躍遷提供了有利的證據。

The thermal-activated carrier transfer processes in Zn0.98Cd0.02O epilayer grown by molecular beam epitaxy was investigated by temperature dependent and time-resolved photoluminescence. The PL of ZnCdO alloy includes free exciton, deep and shallow localized states caused by fluctuations in Cd composition. We also verified the carriers are transferred to the deeper localized states when temperature increased. TRPL spectra gives a strong evidence about the thermal-activated carrier transfer processes in ZnCdO.