Photoreflectance Studies of InGaAsP on (001)InP Strained-layer

• Main Authors: Yang,Biing-Feng, 楊秉峰
• Other Authors: Jan,Gwo-Jen
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/34300117169665370937

碩士 === 國立臺灣大學 === 光電(科學)研究所 === 84 === A series of InGaAsP strained-layer multiple quantum well samples were grown on (001) InP substrates by gas source MBE to investigate the inter-subband transitions in compressively strained wells with the use of temperature-dependent PhotoReflectance(PR) spectroscopic technique. The well width of square wells varies from 50, 80, 100 to 120 angstrom under keeping strain constant. Applying the simple quantum-well model, we have calculated the inter-subband transition energies by taking into account both strain and quantum-size effects. Then, the inter-subband transition energy features of the PR spectra fitted by First Derivative Fitting Function of Gaussian Form to obtain corresponding transition energies and broadening parameters would be identified. In addition to parity-allowed transitions, parity-forbidden transitions are also observed. Being lacking of definite knowledge of many quaternary parameters, all InGaAsP material parameters used in theoretical calculation were obtained by linear interpolation. Therefore, the known values of material parameters of related binaries were necessary. Good agreement with experimental values of InGaAsP barrier bandgap, we can demonstrate that the composition control in process was very precise. Furthermore, the temperature variation of transition energies is also well satisfied for the Varshni equation.