Photoluminescence and Phototreflectance characterization of InGaAsN/GaAs single quantum well

Autor: 楊岳霖
Rok vydání: 2002
Druh dokumentu: 學位論文 ; thesis
Popis: 90
InGaAsP/InP quantum well structures are used to fabricate the laser devices for fiber communication application because the wavelength range is from 1.3μm to 1.5μm. In addition, the lattice match of InGaAsP/InP heterojunction can be achieved so the quality of quantum well can be well controlled. But the small band offset of InGaAsP/InP causes the low characteristic temperature due to the poor electron confinement in quantum well. A new material system, InGaAsN/GaAs, was reported to improve the weakness. With nitrogen doped, the interaction of highly localized N states with the extended states of the semiconductor matrix leads to the formation of two conduction subbands E- and E+. The wavelength emitted from InGaAsN/GaAs quantum well will increase to 1.3μm. As InGaN material, however, it is a challenge for the modern eputaxy growth techniques to control the nitrogen composition and distribution in InGaAs. In molecular beam epitaxy (MBE) growth process, the control of the nitrogen composition and the quality of quantum wells has started the first step. There are still some difficulties in metal-organic chemical vapor deposition (MOCVD) process. The growth rate of MOCVD is more rapid than that of MBE so MOCVD process is more suitable for mass fabrication. Therefore, InGaAsN grown by MOCVD is still under development. In this thesis, we measured the temperature-dependent photoreflectance (PR) spectra and temperature-dependent photoluminescence (PL) spectra of In0.3Ga0.7AsN/GaAs and In0.3Ga0.7As0.998N0.002/GaAs single quantum well grown by MOCVD and discussed the optical properties of the samples. On the condition of the same In and Ga composition, we compared the electron transition energy in quantum well with and without nitrogen atoms. In PR spectra, the transition energy was enlarged with doped nitrogen and the same phenomena was also found in PL spectra. Moreover, we observed two unusual features obvious below the transition energy in PL spectra of lower growth temperature sample C02211.
Databáze: Networked Digital Library of Theses & Dissertations
Externí odkaz: