Growth of rocksalt-structured Mg_xZn_{1− x}O (x > 0.5) films on MgO substrates and their deep-ultraviolet luminescence

Abstract

Single-phase rocksalt-structured Mg x Zn1− x O (x > 0.5) alloy films were grown on MgO substrates using the mist chemical vapor deposition method. A specular surface with a step and terrace structure was obtained. The bandgap was tuned from 5.9 to 7.8 eV as x varied from 0.5 to 1. Deep ultraviolet cathodoluminescence, stemming from near band edge transitions, was observed for Mg0.57Zn0.43O in the 4.8–5.5 eV range, peaking at ∼5.1 eV (∼240 nm) in the 12–100 K range.

Epitaxial Growth and Bandgap Control of Ni1−xMgxO Thin Film Grown by Mist Chemical Vapor Deposition Method

“…In previous studies, we reported the epitaxial growth of NiO thin films on α-Al2O3 substrates via mist chemical vapor deposition (CVD) [7]. By this method, highquality oxide thin films can be grown at atmospheric pressure and semiconductor alloy crystals such as MgxZn1-xO [8,9] and (AlxGa1-x)2O3 [10] can be easily obtained by mixing precursor source solutions.…”

Vacuum Ultraviolet Emission Properties of Rocksalt‐Structured MgZnO Microcrystals Prepared on Quartz Glass Substrates

“…Recently, we have succeeded in growth of atomically flat RS-MgZnO thin films on MgO substrates by the mist chemical vapor deposition (mist CVD) method. [17][18][19] The epitaxial films exhibited cathodoluminescence (CL) peaks located in a range from 5.09 eV (4.91 eV) at 6 K (300 K) for x ¼ 0.61 to 6.24 eV (6.05 eV) at 6 K (300 K) for x ¼ 0.95. [15,[17][18][19][20] The energy difference between the E g and CL peak positions is defined as the Stokes-like shift.…”

“…[17][18][19] The epitaxial films exhibited cathodoluminescence (CL) peaks located in a range from 5.09 eV (4.91 eV) at 6 K (300 K) for x ¼ 0.61 to 6.24 eV (6.05 eV) at 6 K (300 K) for x ¼ 0.95. [15,[17][18][19][20] The energy difference between the E g and CL peak positions is defined as the Stokes-like shift. The origin of the relatively large Stokes-like shift of 0.8-0.9 eV is a debatable issue.…”

“…the exciton localization at certain trapping centers surely give the observation of the DUV and VUV luminescence, [15,[17][18][19][20] exact nature of the phenomenon has not been clarified yet. There is no doubt that investigation of the origin will bring us developments of DUV and VUV emitters using the RS-MgZnO.…”

Pure deep-ultraviolet cathodoluminescence from rocksalt-structured MgZnO grown with carbon-free precursors

“…We previously reported DUV emissions from rocksalt MgZnO films at the peak energies of 4.88-5.21 eV in their cathodoluminescence (CL) spectra at low temperatures below 100 K. 12,13) However, besides the DUV emissions, unintended UV and blue emission peaks were observed. It was hard to obtain pure DUV emission especially at room temperature (RT).…”