|
|
 Creation
of super-hetero-nanostructures for novel opto electronic quantum devices
Watanabe Lab
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. |
|
 |
|
 |
