Thermally activated luminescence in InN nanowires

The photoluminescence from InN nanowires is known to decrease in magnitude with increasing temperature up to 300 K. Here it is shown that the luminescence reappears at higher temperatures, and continues to increase in intensity with increasing temperature up to 600 K. The high temperature luminescence has similar features as the low temperature spectrum, however the magnitude of the high temperature peaks show activated temperature dependence not observed at low temperatures. This suggests that the high temperature luminescence is due to the thermal excitation of charge from long-lived trap states into the conduction band where it then relaxes radiatively.