Dopant activation in Sn-doped Ga2O3 investigated by X-ray absorption spectroscopy
[4];
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
- SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., CA (United States). Dept. of Materials Science and Engineering
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- PVcomB, Kompetenzzentrum Dünnschicht- und Nanotechnologie für Photovoltaik, Berlin (Germany)
- Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry Materials Science and Chemical Biology
- Illinois Inst. of Technology, Chicago, IL (United States). Physics Dept.
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource (SSRL)
Doping activity in both beta-phase ($$β$$-) and amorphous (a-) Sn-doped gallium oxide (Ga2O3:Sn) is investigated by X-ray absorption spectroscopy (XAS). A single crystal of $$β$$-Ga2O3:Sn grown using edge-defined film-fed growth at 1725 °C is compared with amorphous Ga2O3:Sn films deposited at low temperature (<300 °C). Our XAS analyses indicate that activated Sn dopant atoms in conductive single crystal $$β$$-Ga2O3:Sn are present as Sn4+, preferentially substituting for Ga at the octahedral site, as predicted by theoretical calculations. In contrast, inactive Sn atoms in resistive a-Ga2O3:Sn are present in either +2 or +4 charge states depending on growth conditions. These observations suggest the importance of growing Ga2O3:Sn at high temperature to obtain a crystalline phase and controlling the oxidation state of Sn during growth to achieve dopant activation. Many optoelectronic devices incorporate a transparent conducting oxide (TCO) to transport charge carriers and photons to and from active semiconductor layers. An outstanding material challenge is to develop a wide-bandgap TCO with both small electron affinity and high donor concentration (Fermi energy), enabling a low-loss electron-selective contact for emerging materials with high conduction-band energies, including GaN, Cu2O, and n-type silicon.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Center for Next Generation of Materials by Design: Incorporating Metastability (CNGMD)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC36-99GO10337
- OSTI ID:
- 1371047
- Journal Information:
- Applied Physics Letters, Vol. 107, Issue 25; Related Information: CNGMD partners with National Renewable Energy Laboratory (lead); Colorado School of Mines; Harvard University; Lawrence Berkeley National Laboratory; Massachusetts Institute of Technology; Oregon State University; SLAC National Accelerator Laboratory; ISSN 0003-6951
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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