利用光激發於結合光子晶體的類型二量子井之研究

Abstract

本篇論文為結合光子晶體與第二型量子井之研究。第二型量子井因其介面放光機制，發光效率較小，但藉由光子晶體共振腔結構，可耦合出頻寬窄且強度高的共振模態。利用電子束微影術，乾式蝕刻及選擇性濕式蝕刻成功製作出光子晶體共振腔結構，且此透過適當設計的光子晶體共振腔具有高品質因子特性。實驗中，在溫度77K 下，我們利用顯微光激發螢光量測系統成功得到具有高達15170品質因子的單模共振模態。從以知文獻中，這是在結合光子晶體共振腔結構的第二型量子井材料中，第一次量測到具有高達104 級數的品質因子。

In this research, we studied the light emission characteristics of GaAs/GaAsSb type II heterostructures in a photonic nanocavity. In a type II heterostructure, because of the spatial separation of electrons and holes, light emission efficiency is typically very small. However, by coupling the emission peak with the cavity mode, we are able to obtain sharp and intense emission from the type II heterostructure. The nanocavity was fabricated in a suspended thin film photonic crystal. The defect cavity was specially designed to have the desired cavity mode with a high Q value. E-beam lithography, dry etching and selective wet chemical etching were used to fabricate the nanocavity. The emission spectrum was measured by a micro-photoluminescence system using optical pumping. At 77K, an emission peak at 1004nm with a very high Q factor of 15170 was obtained. To our knowledge, this is the first time that a type-II heterostructure emission was coupled to a photonic nanocavity with a very sharp emission and a high Q value.