Enhanced luminescence efficiency in growth interrupted single quantum wells by atomic hydrogen

Abstract

Several groups have demonstrated smoothing of (Al,Ga)As/GaAs quantum well heterointerfaces by growth interrupts (GI). Such quantum wells (QW) usually exhibit multiple narrow line emission spectra where the energy and separation of the peaks is consistent with large lateral islands varying in height by a monolayer. Unfortunately, the integrated emission can be reduced by an order of magnitude as a result of GI. Time decay measurements suggest that GI leads to the incorporation of non-radiative centres. The lifetime and luminescence efficiency can be recovered by annealing the samples for 2h in a hydrogen plasma. The H passivates non-radiative centres but does not degrade the smoothness of the interfaces. These results may have important consequences for the optical and electrical properties of quantum devices