Influence of growth temperature of p-GaN layer on the characteristics of InGaN/GaN blue light emitting diodes

Optimisation for p-GaN epitaxial growth temperature ranges from 920°C to 1020°C was successfully conducted on InGaN/GaN blue light-emitting diodes (LEDs). These InGaN/GaN blue LEDs have been grown on patterned sapphire substrates (PSS) via metal organic chemical vapour deposition (MOCVD). The significance of p-GaN growth temperature was studied in detail according to the structural and optoelectronic performances of InGaN/GaN blue react to depth mechanism of surface evolution to LEDs grown on PSS. From experimental analysis, increment in the epitaxial growth temperature of p-GaN layer caused the crystalline quality of GaN and structural properties slightly improve. Other than that, there are decrement of RMS roughness and PL FWHM due to the increment in the epitaxial growth temperature of p-GaN layer. However, the epitaxial growth temperature of p-GaN increase led to no improvement of optoelectronic properties of InGaN/GaN blue LEDs. The LEDs with higher epitaxial growth temperature of the p-GaN layer show poorer optoelectronic properties. Therefore, the optimised epitaxial growth temperature of the p-GaN layer is of significant importance in achieving highly efficient InGaN/GaN blue LEDs.Besides that, introducing PSS as the substrate did not demonstrate high impact to achieve better performance LEDs. Further improvement of the p-GaN layer crystalline and structural quality might be required for the optimisation of the optoelectronic properties of InGaN/GaN blue LEDs.