High Resistivity and High Mobility in Localized Beryllium-Doped InAlAs/InGaAs Superlattices Grown at Low Temperature

Abstract

InAlAs:Be/InGaAs superlattices grown at low temperatures were investigated in this study. To obtain the highest resistivity and mobility simultaneously, a growth temperature above 200 °C was applied. The electrical properties were conducted via Hall effect measurement and a photoresponse test. The experimental results demonstrate that the sample grown at 257.5~260 °C exhibits the highest resistivity (1290 Ω × cm) and lowest carrier concentration (3.18 × 1014 cm−3), along with the highest mobility (187.2 cm2/Vs). Furthermore, the highest photoresponse (1.21) relative to dark resistivity was obtained under 1500 nm excitation. The optimized growth parameter of InGaAs/InAlAs multilayered structures is of great significance for fabricating high-performance terahertz photoconductive semiconductor antennas.