Group III impurity doped ZnO thin films were deposited on MgAl2O3 substrates using a simple low temperature two-step deposition method involving atomic layer deposition and hydrothermal epitaxy. Films with varying concentrations of either Al, Ga, or In were evaluated for their optoelectronic properties. Inductively coupled plasma atomic emission spectroscopy was used to determine the concentration of dopants within the ZnO films. While Al and Ga-doped films showed linear incorporation rates with the addition of precursors salts in the hydrothermal growth solution, In-doped films were shown to saturate at relatively low concentrations. It was found that Ga-doped films showed the best performance in terms of electrical resistivity and optical absorbance when compared to those doped with In or Al, with a resistivity as low as 1.9 mΩ cm and an optical absorption coefficient of 441 cm−1 at 450 nm.
Mughal AJ, Carberry B, Oh SH, Myzaferi A, Speck JS, et al. (2017) Optoelectronic properties of doped hydrothermal ZnO thin films. physica status solidi (a): 1600941. Available: http://dx.doi.org/10.1002/pssa.201600941.
This work was funded in part by the Solid State Lighting Program (SSLP), a collaboration between King Abdulaziz City for Science and Technology (KACST), King Abdullah University of Science and Technology (KAUST), and University of California, Santa Barbara. A portion of this work was carried out in the UCSB nanofabrication facility, with support from the NSF NNIN network (ECS-03357650), as well as the UCSB Materials Research Laboratory (MRL), which is supported by the NSF MRSEC program (DMR-1121053).