Characterization of majority and minority carrier deep levels in p-type GaN:Mg grown by molecular beam epitaxy using deep level optical spectroscopy
- Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States)
- Materials Department and Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States)
Deep level defects in p-type GaN:Mg grown by molecular beam epitaxy were characterized using steady-state photocapacitance and deep level optical spectroscopy (DLOS). Low frequency capacitance measurements were used to alleviate dispersion effects stemming from the deep Mg acceptor. Use of DLOS enabled a quantitative survey of both deep acceptor and deep donor levels, the latter being particularly important due to the limited understanding of minority carrier states for p-type GaN. Simultaneous electron and hole photoemissions resulted in a convoluted deep level spectrum that was decoupled by emphasizing either majority or minority carrier optical emission through control of the thermal filling time conditions. In this manner, DLOS was able to resolve and quantify the properties of deep levels residing near both the conduction and valence bandedges in the same sample. Bandgap states through hole photoemission were observed at E{sub v}+3.05 eV, E{sub v}+3.22 eV and E{sub v}+3.26 eV. Additionally, DLOS revealed levels at E{sub c}-3.24 eV and E{sub c}-2.97 eV through electron emission to the conduction band with the former attributed to the Mg acceptor itself. The detected deep donor concentration is less than 2% of activated [Mg] and demonstrates the excellent quality of the film.
- OSTI ID:
- 21133999
- Journal Information:
- Journal of Applied Physics, Vol. 103, Issue 6; Other Information: DOI: 10.1063/1.2891673; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Impact of deep levels on the electrical conductivity and luminescence of gallium nitride codoped with carbon and silicon
Shallow and deep level defects in GaN