Increase of the photoluminescence intensity of InP nanowires by photoassisted surface passivation.
As-grown single-crystal InP nanowires, covered with a surface oxide, show a photoluminescence efficiency that strongly varies from wire to wire. We show that the luminescence efficiency of single-crystal InP nanowires can be improved by photoassisted wet chemical etching in a butanol solution containing HF and the indium-coordinating ligand trioctylphosphine oxide. Electron-hole photogeneration, electron scavenging, and oxidative dissolution combined with surface passivation by the indium-coordinating ligand are essential elements to improve the luminescence efficiency. Time traces of the luminescence of surface-passivated wires show strong oscillations resembling the on-off blinking observed with single quantum dots. These results reflect the strong influence of a single or a few nonradiative recombination center(s) on the luminescence properties of an entire wire.
van Vugt
Lambert K
LK
Debye Institute, Condensed Matter and Interfaces, Utrecht University, Post Office Box 80 000, 3508 TA Utrecht, The Netherlands. L.K.vanVugt@Phys.uu.nl
Veen
Sandra J
SJ
Bakkers
Erik P A M
EP
Roest
Aarnoud L
AL
Vanmaekelbergh
Daniël
D