釕酸鍶與氧化鋅奈米複合物之光學旋偏振特性研究

Abstract

本論文研究磁性材料釕酸鍶(SrRuO3)與氧化鋅的自組裝奈米複合物光激發光 的光學旋偏振特性。利用在磁性物質自弦向上及向下的電子能帶結構的不同,在和 半導體界面使不同自弦的電子產生不同的能帶彎曲,造成氧化鋅內部電子自弦分 量堆積(spin accumulation),因而產生具有旋偏振性的光激發光。我們相信藉由這項 機制,能產成自發性自弦極化的半導體並對自弦電子學的應用方面有很大的幫助。

In this thesis, spin polarization of light emission arising from self-assembled ZnO/SrRuO3 nanocomposites, with heterojunctions of magnetic materials and semiconductors, have been investigated. Instead of spin injection by optical or electrical method, the population imbalance between spin-up and spin-down electrons in semiconductors can be achieved by intrinsic distinct band alignments of electrons with different spin orientations at the interface of materials. The energy-band structure induces the selective charge transfer of electrons with opposite spins and generates spin accumulation at the boundary inside ZnO, which then results in circularly polarized photoluminescence. With this mechanism, we believe that self-polarization of electron spin in semiconductors can be achieved and may have a variety of application in spintronics.