High-bright InGaN multiple-quantum-well blue light-emitting diodes on Si (111) using AlN/GaN multilayers with a thin AlN/AlGaN buffer layer

InGaN multiple-quantum-well (MQW) blue light-emitting diodes (LEDs) on Si (111) substrate were grown by metalorganic chemical vapor deposition. Crack-free films on 2-inch wafer were obtained using AlN/GaN multilayers with a thin AlN/AlGaN buffer layer. High-resolution X-ray diffraction (HRXRD) reveals the LED on Si is of high crystalline quality. Dislocation density of MQW active layer was investigated by cathodoluminescence (CL) at room temperature. The operating voltages of 3.7 V and 4.2 V and the output powers of 34.8 μW and 34.5 μW at 20 mA were obtained for the lateral and the vertical conduction, respectively. The forward series resistances are 33 Ω and 42 Ω for the lateral and the vertical conduction, respectively. The EL peaks at 453 nm with a full width at half maximum (FWHM) of 22 nm at 20 mA current. These characteristics are comparable to those of LED on sapphire. Especially, the LED on Si shows a high saturation operating current due to the good thermal conductivity of Si substrate.