Light Emission Study of Free-Standing Quasi-2D-γ-Alumina Grown by Graphene-Assisted Atomic Layer Deposition

Abstract

Intensity-dependent photoluminescence and photoluminescence excitation (PLE) spectroscopy were carried out to probe light emission characteristics and underlying radiative carrier recombination mechanisms in quasi-2D γ-alumina prepared by the two-step graphene-assisted atomic layer deposition method. The room-temperature cw-emission spectrum consists of a single emission peak at ~387 nm, with its intensity exhibiting a weak saturation as excitation power increases, and is attributed to non-interband, intrinsic defect-assisted radiative recombinations. The PLE spectrum obtained for the ~387 nm emission consists of three distinctive, Lorentz line-shaped bands with their peaks in the spectral range of ~3.46–3.82 eV. This study can open a door to engineering radiation hard, robust light emitting nano-opto-electronic devices such as blue-color light emitters based on low-cost crystalline quasi-2D γ-alumina.