Ten-Fold Enhancement of InAs Nanowire Photoluminescence Emission with an InP Passivation Layer.

In this Letter, we demonstrate that a significant improvement of optical performance of InAs nanowires can be achieved by capping the core InAs nanowires with a thin InP shell, which successfully passivates the surface states reducing the rate of nonradiative recombination. The improvements have been confirmed by detailed photoluminescence measurements, which showed up to a 10-fold increase in the intensity of room-temperature photoluminescence from the capped InAs/InP nanowires compared to the sample with core-only InAs nanowires. Moreover, the nanowires exhibit a high stability of total photoluminescence emission strength across temperature range from 10 to 300 K as a result of strong quantum confinement. These findings could be the key to successful implementation of InAs nanowires into optoelectronic devices.