Investigation on physical properties(Bowing Parameter,Composition,and Transition Energy) of Ga1-xAlxAs Alloys

• Main Authors: Lin Yu-Feng, 林裕豐
• Other Authors: Hwia-May Chu
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/46936927355251091174

碩士 === 中原大學 === 應用物理研究所 === 86 === Investigation on the physical properties of Ga1-xAlxAs alloys series in this thesis, and the lowest and higher bang gaps,E0,E0＋Δ0,E1,and E1＋Δ1were calculated , and measured.In earlier study, it is believed that the virtual-crystal approximation is appropriate for analyzing the composition of compounded semiconductors , and the transition energy are linear with composition x.But now, we know that the transition energies have an quadratic form which dependence on alloy composition x , i.e, E(x)＝A＋Bx＋Cx^2 and in which we focused on getting bowing parameter C in the equation by using the dielectric model method, the empirical relation of Woolley, and photoreflectance experiment. Then we estimated the value of spin-oribit splitting Δ1. Theoretical calculated are compared with experiment measurements by photoreflectance and were found that the dielectric model method has a better agreement than the empirical relation of Woolley. Finally, we measured materials of the Ga1-xAlxAs/GaAs single Quantum wells by reflectance experiment.