| AVS 55th International Symposium & Exhibition | |
| Surface Science | Wednesday Sessions |
| Session SS1-WeA |
| Session: | Structure of Oxide Surfaces and Oxide Heterostructures |
| Presenter: | T.C. Lovejoy, University of Washington |
| Authors: | T.C. Lovejoy, University of Washington J. Morales, University of Washington E.N. Yitamben, University of Washington N. Shamir, Nuclear Research Center - Negev, Israel S. Zheng, University of Washington S.C. Fain, University of Washington F.S. Ohuchi, University of Washington M.A. Olmstead, University of Washington |
| Correspondent: | Click to Email |
Experimental studies of the wide band gap semiconductor β-Ga2O3 have been conducted on bulk single crystals using angle resolved photoemission (ARPES) and scanning tunneling microscopy (STM). This system exhibits interesting electronic and optical properties including electroluminescence and resistivity changes upon gas adsorption. In addition, the resistance can vary over many orders of magnitude with annealing and/or electric field treatment of the transparent crystal. Measured valence band dispersion relations are in qualitative agreement with previously reported theoretical calculations. The observed local surface structure is similar to that previously reported for thin films, but the larger scale morphology is characterized by rectangular pits or islands a single unit cell high with lateral sizes varying on the 10-100nm scale. Preliminary experiments with transition metal (Mn) doping reveal changes in electronic structure and surface morphology that may be relevant for application of Mn:Ga2O3 as a dilute magnetic oxide. Work supported by NSF grant DMR-0605601. TCL was supported by an IGERT Fellowship, NSF/NCI DGE 0504573; ENY was supported by an IBM Fellowship. Some experiments were performed at the Advanced Light Source, Berkeley, supported by DOE contract DE-AC02-05CH11231.