InAs QDs on (111)-faceted Si (001) hollow substrates with strong emission at 1300 nm and 1550 nm

Abstract

Highly uniform (111)-faceted Si sawtooth with underlying hollow structures is formed by homo-epitaxy on a U-shaped patterned Si (001) substrate. With in-situ III-V growth on such substrates by the III-V/IV dual chamber molecular beam epitaxy, a high-quality GaAs film is obtained. The (111)-faceted sawtooth structures are found effectively annihilating the antiphase boundaries and terminating mostly the lattice mismatch induced dislocations at the III-V/Si interface, while the hollow structures can effectively reduce the thermal stress. The high-quality GaAs layers on (111)-faceted hollow Si (001) are measured with a threading dislocation density of ∼106 cm−2 via the electron channeling contrast image method. By implementing the designed structure, strong room-temperature emission of InAs/GaAs and InAs/InGaAs quantum dots (QDs) at both O-band (1300 nm) and C/L-band (1550 nm) telecommunication wavelengths are achieved on Si (001) substrates. The O-band emission of InAs/GaAs QDs on Si (001) shows similar intensity to that on the GaAs substrate.