Far-infrared〜THz light emitter based on InAs/GaSb quantam cascade structures

基于InAs/GaSb量子级联结构的远红外〜太赫兹光发射器

基本信息

批准号：
11355012
负责人：
OHNO Hideo
金额：
$ 17.34万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11355012/
关键词：
InAs GaSb quantum cascade structure quantum well structure subband laser electroluminescence far-infrared THz

项目摘要

Far-infrared〜THz intersubband light emitters based on InAs/GaSb quantum cascade structures were investigated theoretically and experimentally. In order to realize high efficiency light emitter, intersubband electroluminescence was characterized by step-scan Fourier transform infrared spectrometer(FT-IR) and low-temperature cryostat.The summary of the research results are :1. Calculated threshold current density of type-II InAs/GaSb intersubband emitter showed that it was about one-fifth as small as that of type-I GaAs/AlGaAs and GaInAs/AlInAs systems.2. Intersubband electroluminescence from InAs/AlSb quantum cascade structures having large tunability of emission wavelength was observed for the first time.3. Temperature and structure dependence of intersubband electroluminescence was instigated by step-scan FT-IR and low-temperature cryostat. Calculated subband structures were found to be in close agreement with extperimental results.4. Optical properties of InAs/AlSb multi-quantum wells epitaxially grown on GaAs substrates with a buffer layer were shown to be dependent on the type of the interface bond and buffer layer material. X-ray diffraction measurements revealed that lattice matching between the average lattice constant of multi-quantum well and the buffer layer plays a key role in determining the optical properties.5. Carrier recycling in type-II InAs/GaSb quantum cascade structures was investigated. It has been observed that the emission power was proportional to the periods of cascade structures, which indicated that injected carriers were recycled in type-II cascade structures.6. The new type-II InAs/GaSb light emitting structures was proposed. Theoretical calculation showed that new structures could emit electro-magnetic waves in the THz region without going to an extreme design.

为了实现高效率的光发射器，对基于InAs/GaSb量子级联结构的远红外〜THz子带间电致发光进行了理论和实验研究，并利用步进扫描傅里叶变换红外光谱仪（FT-IR）和低光谱仪对子带间电致发光进行了表征。研究结果总结如下： 1．计算出II型InAs/GaSb子带间发射极的阈值电流密度：其尺寸约为I型GaAs/AlGaAs和GaInAs/AlInAs体系的五分之一。2．首次观察到发射波长可调的InAs/AlSb量子级联结构的子带间电致发光。步进扫描 FT-IR 激发了子带间电致发光的结构依赖性，并发现计算出的子带结构与子带间结构相关。与实验结果非常一致。4.在带有缓冲层的GaAs 衬底上外延生长的InAs/AlSb 多量子阱的光学性质取决于界面键合类型和缓冲层材料。多量子阱与缓冲层的平均晶格常数的匹配对II型InAs/GaSb量子的载流子回收起着关键作用。对级联结构进行了研究，发现发射功率与级联结构的周期成正比，这表明注入的载流子在II型级联结构中得到了循环利用。 6．理论计算表明，新结构无需进行极端设计即可在太赫兹区域发射电磁波。