Kinetic growth of self-formed In_2O_3 nanodots via phase segregation: Ni/InAs system

摘要

Highly compact In_2O_3 nanodots with uniform size were synthesized by a novel approach via direct annealing of Ni/InAs samples at temperatures over 250 °C. The In_2O_3 nanodots were formed by solid diffusion between nickel and indium arsenide (InAs) and phase segregation via a catalyst-assisted kinetic process. By controlling the annealing time and ambient conditions, the size and density of In _2O_3 nanodots can be controlled. From photoluminescence (PL) measurements, two distinct peaks located at ～430 and ～850 nm, corresponding to 2.9 and 1.5 eV for In_2O_3 nanodots, can be observed. The peaks originate from radioactive recombination centers such as oxygen vacancies or indium interstitials inside In_2O_3 nanodots. The periodic array of Ni microdiscs with diameters and interdisc spacing of ～5 and ～10 μm on InAs substrate surface prepared by a photolithography process demonstrated the precise control of In _2O_3 nanodots at a specific position. Applications for precisely locating optoelectronic nanodevices in combination with electronic nanodevices are envisioned.