Defect phase diagram for doping of Ga2O3
For the case of n-type doping of β-Ga2O3 by group 14 dopants (C, Si, Ge, Sn), a defect phase diagram is constructed from defect equilibria calculated over a range of temperatures (T), O partial pressures (pO2), and dopant concentrations. The underlying defect levels and formation energies are determ...
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2018-04-01
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| Series: | APL Materials |
| Online Access: | http://dx.doi.org/10.1063/1.5019938 |
| _version_ | 1811269702595379200 |
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| author | Stephan Lany |
| author_facet | Stephan Lany |
| author_sort | Stephan Lany |
| collection | DOAJ |
| description | For the case of n-type doping of β-Ga2O3 by group 14 dopants (C, Si, Ge, Sn), a defect phase diagram is constructed from defect equilibria calculated over a range of temperatures (T), O partial pressures (pO2), and dopant concentrations. The underlying defect levels and formation energies are determined from first-principles supercell calculations with GW bandgap corrections. Only Si is found to be a truly shallow donor, C is a deep DX-like (lattice relaxed donor) center, and Ge and Sn have defect levels close to the conduction band minimum. The thermodynamic modeling includes the effect of association of dopant-defect pairs and complexes, which causes the net doping to decline when exceeding a certain optimal dopant concentration. The optimal doping levels are surprisingly low, between about 0.01% and 1% of cation substitution, depending on the (T, pO2) conditions. Considering further the stability constraints due to sublimation of molecular Ga2O, specific predictions of optimized pO2 and Si dopant concentrations are given. The incomplete passivation of dopant-defect complexes in β-Ga2O3 suggests a design rule for metastable doping above the solubility limit. |
| first_indexed | 2024-04-12T21:46:50Z |
| format | Article |
| id | doaj.art-bd0b283d4c864e0e9654e3e50df13d58 |
| institution | Directory Open Access Journal |
| issn | 2166-532X |
| language | English |
| last_indexed | 2024-04-12T21:46:50Z |
| publishDate | 2018-04-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | APL Materials |
| spelling | doaj.art-bd0b283d4c864e0e9654e3e50df13d582022-12-22T03:15:36ZengAIP Publishing LLCAPL Materials2166-532X2018-04-0164046103046103-910.1063/1.5019938002804APMDefect phase diagram for doping of Ga2O3Stephan Lany0National Renewable Energy Laboratory, Golden, Colorado 80401, USAFor the case of n-type doping of β-Ga2O3 by group 14 dopants (C, Si, Ge, Sn), a defect phase diagram is constructed from defect equilibria calculated over a range of temperatures (T), O partial pressures (pO2), and dopant concentrations. The underlying defect levels and formation energies are determined from first-principles supercell calculations with GW bandgap corrections. Only Si is found to be a truly shallow donor, C is a deep DX-like (lattice relaxed donor) center, and Ge and Sn have defect levels close to the conduction band minimum. The thermodynamic modeling includes the effect of association of dopant-defect pairs and complexes, which causes the net doping to decline when exceeding a certain optimal dopant concentration. The optimal doping levels are surprisingly low, between about 0.01% and 1% of cation substitution, depending on the (T, pO2) conditions. Considering further the stability constraints due to sublimation of molecular Ga2O, specific predictions of optimized pO2 and Si dopant concentrations are given. The incomplete passivation of dopant-defect complexes in β-Ga2O3 suggests a design rule for metastable doping above the solubility limit.http://dx.doi.org/10.1063/1.5019938 |
| spellingShingle | Stephan Lany Defect phase diagram for doping of Ga2O3 APL Materials |
| title | Defect phase diagram for doping of Ga2O3 |
| title_full | Defect phase diagram for doping of Ga2O3 |
| title_fullStr | Defect phase diagram for doping of Ga2O3 |
| title_full_unstemmed | Defect phase diagram for doping of Ga2O3 |
| title_short | Defect phase diagram for doping of Ga2O3 |
| title_sort | defect phase diagram for doping of ga2o3 |
| url | http://dx.doi.org/10.1063/1.5019938 |
| work_keys_str_mv | AT stephanlany defectphasediagramfordopingofga2o3 |