Study on the Optical Characteristics of InAs/GaAs Quantum Dots and InGaN/GaN Multiple Quantum Well

• Main Authors: Cheng-yeh Tsai, 蔡正曄
• Other Authors: C. C. Yang
• Format: Others
• Language: en_US
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/38782898084151717124

碩士 === 國立臺灣大學 === 光電工程學研究所 === 91 === In this thesis, we study the optical properties of InAs/GaAs quantum dots and InGaN/GaN multiple quantum well with PL measurements and pump—probe measurements. We obtain the effect of carrier transfer from shallow dots to deep dots and the carrier transfer mechanisms in the wetting layer through temperature-dependent PL measurements. We also observe bandgap renormalization with power-dependence PL measurements. After rapid thermal annealing, indium diffusion result in an intermixing of hetero-interfaces. In order to study the carrier dynamics of InAs/GaAs QDs, we build a pump-probe system. The effects of phonon bottleneck, carrier—carrier scattering and Auger process are also discussed. We investigate the optical properties of InGaN/GaN quantum wells of different well widths with PL measurements. In order to study the carrier dynamics of InGaN/GaN MQWs with indium aggregation structures, we build a pump-probe system in the UV-blue range for studying ultra-fast carrier dynamics. Decay times of carrier relaxation and recombination in samples of various microstructures are compared for understanding the relations between carrier dynamics and nano-scale structures.