Temperature dependence of the surface plasmon coupling with an InGaN/GaN quantum well

The authors demonstrate the temperature-dependent behavior of the surface plasmon (SP) coupling with two InGaN/GaN quantum-well (QW) structures of different internal quantum efficiencies. The SP modes are generated at the interface between the QW structures and Ag thin films coated on their tops. It is observed that the SP-QW coupling rate increases with temperature. Such a trend may rely on several factors, including the availability of carriers with sufficient momenta for transferring the energy and momentum into the SP modes and possibly the variation of the SP density of state with temperature. Although the required momentum matching condition only needs the thermal energy corresponding to a few tens of Kelvins, the carrier delocalization process results in a significantly higher probability of SP-carrier momentum matching and hence SP-QW coupling. (C) 2007 American Institute of Physics.