Numerical study of strained InGaAs quantum well lasers emitting at 2.33 μm using the eight-band model

We investigate the band structure of a compressively strained In(Ga)As/In 0.53 Ga 0.47 As quantum well (QW) on an InP substrate using the eight-band k · p theory.Aiming at the emission wavelength around 2.33 μm,we discuss the influences of temperature,strain and well width on the band structure and on the emission wavelength of the QW.The wavelength increases with the increase of temperature,strain and well width.Furthermore,we design an InAs /In 0.53 Ga 0.47 As QW with a well width of 4.1 nm emitting at 2.33 μm by optimizing the strain and the well width.     

InP基InAs量子线异常的变温光致发光谱研究北大核心CSCD

制备了InAs/InAlGaAs/InP(001)量子线结构,利用变温光致发光谱(PL)研究了InAs量子线的光学特性.随温度增加InAs量子线PL谱的发光峰位呈异常的S型变化,即:在15K^35K时峰位红移;在35K^55K温度范围内峰位发生了蓝移;随后随温度进一步增加,峰位再次发生红移.分析认为这种S型峰位的变化可能是由于不同温度下载流子的不同复合机制所引起的.     

InP基近红外波段量子线激光器的温度特性研究

制备了InP基近红外波段量子线激光器,在激光器温度特性分析中,观察到了反常的特征温度分布曲线.随着热沉温度增加,在120—180 K时,激光器阈值电流随温度升高出现下降趋势,即出现了负的特征温度.分析认为负特征温度的出现是由于随温度变化载流子再分布引起的.     

Spacer layer thickness fluctuation scattering in a modulation-doped Al_xGa_1-xAs/GaAs/Al_xGa_1-xAs quantum well

We theoretically study the influence of spacer layer thickness fluctuation(SLTF) on the mobility of a twodimensional electron gas(2DEG) in the modulation-doped Al x Ga 1 x As/GaAs/Al x Ga 1 x As quantum well.The dependence of the mobility limited by SLTF scattering on spacer layer thickness and donor density are obtained.The results show that SLTF scattering is an important scattering mechanism for the quantum well structure with a thick well layer.     

Indium-Induced Effect on Polarized Electroluminescence from InGaN/GaN MQWs Light Emitting Diodes

Polarization-resolved edge-emitting electroluminescence （EL） studies of In GaN/GaN MQWs of wavelengths from near-UV （390nm） to blue （468nm） light-emitting diodes （LEDs） are performed. Although the TE mode is dominant in all the samples of InGaN/GaN MQW LEDs, an obvious difference of light polarization properties is found in the InGaN/GaN MQW LEDs with different wavelengths. The polarization degree decreases from 52.4% to 26.9% when light wavelength increases. Analyses of band structures of InGaN/GaN quantum wells and luminescence properties of quantum dots imply that quantum-dot-like behavior is the dominant reason for the low luminescence polarization degree of blue LEDs, and the high luminescence polarization degree of UV LEDs mainly comes from QW confinement and the strain effect. Therefore, indium induced carrier confinement （quantum-dot-like behavior） might play a major role in the polarization degree change of InGaN/GaN MQW LEDs from near violet to blue.     

A 10.7 μm InGaAs/InAlAs Quantum Cascade Detector

A 10.7μm quantum cascade detector based on lattice matched InGaAs/InAlAs/InP is demonstrated and characterized in terms of responsivity, resistivity and detectivity. The device operates in the 8 14μm atmospheric window up to 140 K and shows a peak reponsivity of 14.4mA/W at 78K. With a resistance-area product value of 159Ωcm^2, the Johnson noise limited detectivity D^＊J is 2.8 × 10^9 Jones （cmHz^1/2W^-1） at 78K.     

A grating-coupled external cavity InAs/InP quantum dot laser with 85-nm tuning range

The optical performance of a grating-coupled external Continuous tuning from 1391 nm to 1468 nm is realized at cavity laser based on InAs/InP quantum dots is investigated. an injection current of 1900 mA. With the injection current increasing to 2300 mA, the tuning is blue shifted to some extent to the range from 1383 nm to 1461 nm. By combining the effect of the injection current with the grating tuning, the total tuning bandwidth of the external cavity quantum-dot laser can reach up to 85 nm. The dependence of the threshold current on the tuning wavelength is also presented.     

Exciton–phonon interaction in Al_(0.4)Ga_(0.6)N/Al_(0.53)Ga_(0.47)N multiple quantum wells

The exciton-phonon interaction in Al_(0.4)Ga_(0.6)N/Al_(0.53)Ga_(0.47)N multiple quantum wells(MQWs) is studied by deepultraviolet time-integrated and time-resolved photoluminescence(PL).Up to four longitudinal-optical(LO) phonon replicas of exciton recombination are observed,indicating the strong coupling of excitons with LO phonons in the MQWs.Moreover,the exciton-phonon coupling strength in the MQWs is quantified by the Huang-Rhys factor,and it keeps almost constant in a temperature range from 10 K to 120 K.This result can be explained in terms of effects of fluctuations in the well thickness in the MQWs and the temperature on the exciton-phonon interaction.