Control of electrons and holes by quantum rings and related nanostructures and its device applications

为了拓展纳米电子学研究的前沿，我们探索了量子环（QR）结构与量子点（QD），棒和线并联的潜力。注意力主要集中在II型GaSb基纳米结构上，其中空穴被选择性地限制，而电子被驱动到外部。两种方案的自组织形成的（GaAl）Sb量子点已被研究;在一个方案中，环形量子态的空穴形成，而电子被限制在环状轨道外的一个带正电的GaSb量子点在其他。提出并分析了利用QR态产生多极辐射的可能性。提出并实现了一种新的光电探测器器件，其中光生空穴被GaSb空穴捕获，并通过近旁路通道调制电流。此外，我们还展示了一种独特的方案，以沿着多原子台阶约20- 40 nm的周期性排列InGaAs量子点，也是新颖的单电子晶体管的基础上连接到一个单独的InAs量子点的微小电极。

To expand the forefront of nanoelectronics research, we have explored potentials of quantum ring (QR) structures in parallel with quantum dots (QDs), rods, and wires. Attentions have been focused mainly on type II GaSb based nanostructures, where holes are selectively confined, while electrons are driven outside. Two schemes for the self-organized formation of (GaAl)Sb QRs have been studied; in one scheme, ring-shaped quantum states of holes are formed, whereas electrons are confined in ring-like orbits just outside a positively charged GaSb QD in the other. A possibility to generate multi-pole radiations by making use of QR states has been proposed and analyzed. A new photodetector device has been proposed and realized, in which photo-generated holes are trapped by GaSb holes and modulate the current flow through a near bye channel. In addition, we have demonstrated a unique scheme to align InGaAs QDs along multi-atomic steps of about 20-40nm in periodicity and also novel single-electron transistors based on tiny electrodes attached to an individual InAs QD.