Applied Science and Convergence Technology 1998; 7(4): 334-340
Published online November 1, 1998
Copyright © The Korean Vacuum Society.
In-Soo Kim,Jeoog-Sik Son,Cheul-Wook Lee,In-Ho Bae,Jae-Youog Leem,Byung-Kuk Han,Young-Nam Shin
Photoreflectance (PR) measurents have been performed on In_xGa_(1-x)As/GaAs grown by molecular beam epitaxy (MBE). Bandgap (E。) of In_xGa_(1-x)As epilayer measured from PR was separated as heavy-hole (E。(HH)) and light-hole (E。(LH)) by strain effect. The compositions and the strains of epilayer were obtained from the energy value of E。(HH) and from enegy difference of E。(HH) and E。(LH), respectively. In addition, the PR signal of E。(LH) was diminished below 160 K. The interface electric field (E) of InGaAs/GaAs was increased from 0.75×10^5 V/㎝ to 2.66×10^5 V/㎝ as In composition increased, which was calculated from Franz-Keldysh oscillation (FKO) peaks. As the temperature dependence of the PR signal at x=0.09 sample, we obtained Varshni and Bose-Einstein coefficients.