| Impurity or State | Binding Energy (meV) | Reference |
| a donor (residual in HVPE, MOCVD) | 34.4 | Present work [12] [13] [14] |
| b donor* (residual in HVPE) | 31.3 | Present work [12] [13] [14] |
| c donor (residual in HVPE, MOCVD) | 30.4 | Present work [12] [13] [14] |
| d donor (residual in HVPE, MOCVD) | 28.8 | Present work [12] [13] [14] |
| e donor* (residual in HVPE) | 27.5 | Present work [12] [13] [14] |
| Si donor (Si-doped material) | 22 | Present work [12] [13] [14] |
| Donor (residual in HVPE) | 34.5 | [28] [29] |
| Donor in Si-doped sample | ~29 | [31] |
| Donors (residual in HVPE) | 31.1, 33.8 | [30] |
| Si acceptor (Si-doped material) | 224 | Present work [12] [14] |
| Mg acceptor (Mg-doped material) | 224 | Present work [23] |
| Free exciton | 18-27 |
Various; see [10] |
| Free exciton | 26.4 | Present work ( [10] [11] [12] [13], [19]) |
| *Existence uncertain | ||
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