トップ QNERCとは 運営委員会 研究グループ 研究施設 研究室 出版物 討論会 講演 ニュースレター 旧職員 関連リンク 連絡先	トップ > 旧職員 > 渡辺研究室 Creation of super-hetero-nanostructures for novel opto electronic quantum devices 渡辺研究室 http://www.pe.titech.ac.jp/WatanabeLab/index.html Objective The purpose of this study is to develop novel devices using quantum effect in super-hetero-nanostructure, which consists of super lattices or nano-crystals made of dissimilar materials including insulators, metals, as well as semiconductors. Research Field Quantum effect devices, Hetero-epitaxial growth engineering Research Theme Quantum cascade lasers using CaF2/CdF2 super lattices have been proposed theoretically as schematically shown in Fig.1. Experimentally, we have demonstrated epitaxial growth of CaF2/CdF2 super lattices and room temperature negative differential resistance of triple-barrier (TB) and double-barrier (DB) resonant tunneling diode structures. High peak-to-valley current ratio is observed for DBRTD structures even at room temperature as shown in Fig.2. This result indicates formation of sharp sub bands in CaF2/CdF2/CaF2 quantum hetero structure. Fig.1 : Schematics of CaF2/CdF2 intersubband transition laser (quantum cascade laser) Fig.2 : Room temperature negative differential resistance of CaF2/CdF2 double-barrier resonant tunneling diode.