Si delta doping in a GaN barrier layer of InGaN∕GaN multiquantum well for an efficient ultraviolet light-emitting diode

Abstract

The effect of Si delta doping of the GaN barrier on the optical and electrical properties of an InGaN∕GaN ultraviolet light-emitting diode (UV LED) was studied. The photoluminescence (PL) intensity of the multiquantum well (MQW) and the output power of UV LED with an emission wavelength of 385 nm were greatly improved as the result of introducing a Si delta-doping layer in GaN barrier of an InGaN∕GaN MQW. A temperature-dependent PL study showed that the integrated intensity of the PL of a MQW with a Si delta-doping layer was slowly quenched with increasing temperature compared to that of a MQW without a Si delta-doping layer. The improvement in thermal stability and optical power of the UV MQW and LED is attributed to an increase in the injection of electrons from the Si delta-doped GaN barrier layer into the InGaN quantum well layer and an increase in hole accumulation due to the higher valance band offset of a Si delta-doped GaN barrier layer in a MQW structure.