Electronic structures of uncapped In(Ga)As nanoislands grown on pit-patterned GaAs(001) substrate

Abstract In this paper, we systematically investigate the electronic structures of uncapped In(Ga)As nanoislands grown on pit-patterned GaAs(001) substrate by solving the Schrodinger equations with effective mass approximation, including composition profile (CP), band offset, strain induced deformation potentials, spin-orbit coupling and piezoelectric effect. For pure InAs epilayer, the shallow pit introduces red-shift to interband transition for all aspect ratios and the heavy-hole is localized by the confinement near the inclined hetero-interfaces in circular pit. For InGaAs alloy epilayer, the uniform CP and equilibrium CPs are considered. Due to the Indium segregation, the reduction of interband transition energy can be observed and the localized profile of heavy-hole moves upward visibly. Moreover, the strain relaxation analysis confirms better strain relaxation for nanoisland grown in shallow pit (tan β  = 0.1) compared with same nanoisland grown on flat substrate. The results pave a guideline for designing site-controlled In(Ga)As nanoislands grown in pit for desired applications.