Telecom-wavelength InAs QDs with low fine structure splitting grown by droplet epitaxy on GaAs(111)A vicinal substrates
A. Tuktamyshev, A. Fedorov, S. Bietti, S. Vichi, K. D. Zeuner, K. D. Jöns, D. Chrastina, S. Tsukamoto, V. Zwiller, M. Gurioli, S. Sanguinetti
Abstract
We present self-assembly of InAs/InAlAs quantum dots by the droplet epitaxy technique on vicinal GaAs(111)A substrates. The small miscut angle, while maintaining the symmetries imposed on the quantum dot from the surface, allows a fast growth rate thanks to the presence of preferential nucleation sites at the step edges. A 100 nm InAlAs metamorphic layer with In content ≥50% directly deposited on the GaAs substrate is already almost fully relaxed with a very flat surface. The quantum dots emit at the 1.3 μm telecom O-band with fine structure splitting as low as 16 μeV, thus making them suitable as photon sources in quantum communication networks using entangled photons.