The role of the quantum-confined Stark effect in an InGaN/GaN quantum well during its coupling with surface plasmon for light emission enhancement

We analyze the contribution of the screening of the quantum-confined Stark effect (QCSE) to the light emission enhancement behavior in the surface plasmon (SP) coupling process with an InGaN/GaN quantum well (QW). From the measurements of excitation power-dependent photoluminescence and time-resolved photoluminescence (TRPL), and the fitting to the TRPL data based on a rate-equation model, it is found that when the excitation level is high, the QCSE screening effect not only contributes significantly to the emission enhancement, but also enforces the SP coupling process because of the blue shift of emission spectrum caused by the screening effect. Therefore, the emission strength from SP radiation, relative to that from QW radiative recombination, increases with the excited carrier density.