The suitability of Ti as a band gap modifier for α-Ga2O3 was investigated, taking advantage of the isostructural {\alpha}-phases and high band gap difference between Ti2O3 and Ga2O3. Films of Ti:Ga2O3, with a range of Ti concentrations, synthesized by atomic layer deposition on sapphire substrates, were characterized to determine how crystallinity and band gap vary with composition for this alloy. The deposition of crystalline α-(TixGa1−x)2O3 films with up to x~5.3%, was demonstrated. At greater Ti concentration, the films became amorphous. Modification of the band gap over a range of ~ 270 meV was achieved across the crystalline films and a maximum change in band gap from pure α-Ga2O3 of ~1.1 eV was observed for the films of greatest Ti fraction (61% Ti relative to Ga). The ability to maintain a crystalline phase at low fractions of Ti, accompanied by a significant modification in band gap shows promise for band gap engineering and the enhancement in versatility of application of α-Ga2O3 in optoelectronic devices.
@article{arxiv.2006.01422,
title = {Ti alloyed $\alpha$-Ga$_2$O$_3$: route towards wide band gap engineering},
author = {A. Barthel and J. W. Roberts and M. Napari and T. N. Huq and A. Kovács and R. A. Oliver and P. R. Chalker and T. Sajavaara and F. C-P. Massabuau},
journal= {arXiv preprint arXiv:2006.01422},
year = {2020}
}