Theoretical analysis of lasing characteristics of stacked lnGaN quantum dot lasers from atomic scale

原子尺度叠层氮化镓量子点激光器激光特性的理论分析

• 批准号: 12650004
• 负责人: SAITO Toshio
• 金额: $ 1.6万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650004/
• 关键词: GaN; lnGaN; quantum dot; electronic structure; fight-binding method; piezoelectric effect; Stark effect; wave function overlap

We have analyzed the electronic structures of ln_<0.2>Ga_<0.8>N pyramidal quantum dots (QDs) in a GaN barrier layer using a polarization-potential dependent sp^3 tight-binding method. A valence-force-field method using the Keating potential was used for the strain and atom-position calculations. For the QD with the diameter 86.4 A, height of 20.8 A, and facet inclination angle of 30 degree, the maximum piezoelectric field is calculated to be1.64 MV/cm. The energy gap shows a red shift of 0.100 eV due to the quantum-confined Stark effect. The field causes a spatial separation of the electron and hole wave functions in the QD. The number of electron-hole pairs, which can screen the field totally, is estimated as a function of the diameter. We find that 13 electron-hole pairs are required for the complete field screening for the QD with the diameter 86.4 A. In experiments by Damilano et al., the photoluminescence peak energy, E_<PL>, of 2.71 eV (at room temperature) was measured for the MBE-grown In_<0.2>Ga_<0.8>N QDs with the similar QD size ; diameter = 100 A, heitht = 20 A. Eg = 2.706 eV for the pyramidal QD is in better agreement with the measured energy, E_<PL> = 2.71 eV, than Eg = 2.502 eV for the prismatic QD.

利用极化势相关的sp^3紧密结合方法分析了氮化镓势垒层中ln_<0.2>Ga_<0.8>N金字塔量子点（QDs）的电子结构。采用基廷势的价力场法计算了应变和原子位置。对于直径86.4 A、高20.8 A、面倾角为30度的QD，计算得到最大压电场为1.64 MV/cm。由于受量子限制的斯塔克效应，能隙显示出0.100 eV的红移。该场导致量子点中电子波函数和空穴波函数的空间分离。电子-空穴对的数量可以完全屏蔽场，估计为直径的函数。我们发现直径为86.4 A的量子点需要13个电子空穴对才能完成场屏蔽。在Damilano等的实验中，在相似量子点尺寸的_<0.2>Ga_<0.8>N量子点中生长的mbe，测得其光致发光峰值能量为2.71 eV（室温）；直径= 100a，高度= 20a。锥体QD的Eg = 2.706 eV比棱柱形QD的Eg = 2.502 eV更符合测量能量E_<PL> = 2.71 eV。

项目成果

T.Saito: "Electronic Structure of InCaN Quantum Dots in GaN : Atomic Scale Calculations"Extended Abstracts of 2000 Int.Conf.on Solid State Devices and Materials (Sendai, Japan, Aug.29-31, 2000). (2000)

T.Saito：“GaN 中 InCaN 量子点的电子结构：原子尺度计算”2000 年固态器件和材料国际会议的扩展摘要（日本仙台，2000 年 8 月 29-31 日）。

T. Saito, and Y. Arakawa: ""Effects of internal piezoelectric field on electronic states of InGaN quantum dots grown on GaN,""J. of Crystal Growth. (in press).

T. Saito 和 Y. Arakawa：“内部压电场对在 GaN 上生长的 InGaN 量子点的电子态的影响”，J.

T.Saito: "Electronic states of GaN-based quantum dots"Proc.of 5th Symp.on Atomic-Scale Surface and Interface Dynamics (Tokyo, Japan, March 1-2,2001).. 45-48 (2001)

T.Saito：“基于 GaN 的量子点的电子态”Proc.of 5th Symp.on Atomic-Scale Surface and Interface Dynamics（日本东京，2001 年 3 月 1-2 日）.. 45-48 (2001)

T.Saito: "Quantum confined electronic states in In GaN dots embedded in GaN"Proc. of 27th Int. Symp. on Compound Semiconductors. 285-290 (2000)

T.Saito：“嵌入 GaN 中的 In GaN 点中的量子限制电子态”Proc。

T.Saito: "Quantum confined electronic states in InGaN dots embedded in GaN : Tight-binding calculation"Proc.of 27th Int.Symp.on Compound Semiconductors, Monterey, California, 2000. (in press). (2001)

T.Saito：“嵌入 GaN 中的 InGaN 点中的量子限制电子态：紧束缚计算”Proc.of 27th Int.Symp.on 化合物半导体，蒙特利，加利福尼亚州，2000 年。（印刷中）。