N–SrTiO3/p-GaN heterojunctions: A white light-emitting diode with a broad luminescence spectrum

Abstract

We report a white light-emitting diode (LED) based on the n-SrTiO3 (n-STO)/p-GaN heterojunction. The n-STO/p-GaN heterojunction LED shows the good rectification characteristics in the current−voltage measurements and an intense white light emission with a broad luminescence spectrum in electroluminescence (EL) measurements. There are two strong and broad emission bands at the regions from blue to red (450–650 nm, center located at ~525 nm) and from ultraviolet to blue (350–450 nm, center located at ~410 nm), which are respectively derived from the p-type GaN and n-type STO layers. The photoluminescence (PL) spectra indicate that the n-STO film has an emission band from ultraviolet (UV) to blue which is associated with the near band-edge emission and defect-related radiative recombination, and the p-GaN layer has an emission band from blue to red. Our results suggest that n-STO/p-GaN heterojunction is an alternate and effective heterostructure to achieve LEDs with high intense white light emission.