Synthesis and optoelectronic properties of ultrathin Ga(2)O(3)nanowires

摘要

Gallium oxide (Ga2O3) and its most stable modification, monoclinic beta-Ga2O3, is emerging as a primary material for power electronic devices, gas sensors and optical devices due to a high breakdown voltage, large bandgap, and optical transparency combined with electrical conductivity. Growth of beta-Ga(2)O(3)is challenging and most methods require very high temperatures. Nanowires of beta-Ga(2)O(3)have been investigated extensively as they might be advantageous for devices such as nanowire field effect transistors, and gas sensors benefiting from a large surface to volume ratio, among others. Here, we report a synthesis approach using a sulfide precursor (Ga2S3), which requires relatively low substrate temperatures and short growth times to produce high-quality single crystalline beta-Ga(2)O(3)nanowires in high yields. Even though Au- or Ag-rich nanoparticles are invariably observed at the nanowire tips, they merely serve as nucleation seeds while the nanowire growth proceedsviasupply and local oxidation of gallium at the substrate interface. Absorption and cathodoluminescence spectroscopy on individual nanowires confirms a wide bandgap of 4.63 eV and strong luminescence with a maximum similar to 2.7 eV. Determining the growth process, morphology, composition and optoelectronic properties on the single nanowire level is key to further application of the beta-Ga(2)O(3)nanowires in electronic devices.