Enhanced luminescence properties of InAs nanowires via organic and inorganic sulfide passivation

: InAs nanowires (NWs) have been considered to be highly suitable for future nanoscale photonic applications in mid-wave infrared region. However, progress in this area has been seriously hampered because of the poor radiative efficiency of InAs NWs attributed to their non-radiative (NR) surface. Herein, we demonstrated that a significant improvement of optical performances of InAs NWs grown by chemical vapor deposition could be achieved via sulfur passivation process. Luminescence properties of InAs NWs via organic sulfide (ODT) and inorganic sulfide ((NH4)2S) passivation were investigated by detailed photoluminescence (PL) measurement, which exhibited ∼17-fold enhancement in the intensity of optical emission compared to unpassivated InAs NWs. Moreover, the results of this investigation revealed that compared to ODT passivation, (NH4)2S passivation provided a more effective method to enhance the luminescence intensity even up to room temperature. This improvement of optical emission arises from the efficient passivation of surface defect states which act as competing NR centers. Furthermore, the stability of the passivated InAs NWs was investigated by PL measurement as a function of storage time in air. These findings are important for the successful implementation of optoelectronic devices based on InAs NWs.