The influence of well thickness on the photoluminescence properties of blue-violet light emitting InGaN/GaN multiple quantum wells

Photoluminescence (PL) properties of four blue-violet light emitting InGaN/GaN multiple quantum well (MQW) structures with varying well thickness were studied by means of room temperature PL (RTPL) spectra and temperature-dependent PL (TDPL). From the TDPL, two different kinds of dependencies of PL peak energy with increasing temperature are observed, i.e. an S-shape dependence and an inverted V-shape one. Since the In content in MQW structures is nearly identical for four samples, the difference in luminescence properties is mainly attributed to an increase in localization effects with increasing well thickness.