High photoluminescence efficiency of InGaAs/GaAs quantum dots self-formed by atomic layer epitaxy technique

We investigated the photoluminescence (PL) intensity of InGaAs/GaAs quantum dots self-formed by atomic layer epitaxy (ALE) technique as a function of temperature. We report that the reduction of PL intensity following a temperature increase was two-orders smaller in the ALE-grown dots than in the dots grown by molecular beam epitaxy via Stranski–Krastanov mode. Measuring the radiative lifetimes and evaluating the temperature dependence of PL intensity, we conclude that the nonradiative channel outside the dots caused the PL reduction.