Table 4.
Intertrap tunneling and variable range hopping parameters of ZnO:N films deposited at gas ratio of Ar:O2:N2 = 50:10:40 (sample 2.1) and treated by RTA at 550 °C (sample 2.1): qφa—effective thermally activation energy; w—mean distance between deep levels; qφt and Nt—energy position and density of deep levels, respectively, in the ZnO energy gap; T0—characteristic temperature; aB,ZnO—Bohr radius of the localized states in the ZnO energy gap; N(ε)—density of localized states; Rm and ∆W—most probable hopping distance and energy difference of deep levels, respectively.
| Parameters | As-Deposited ZnO:N |
After RTA at 550 °C |
|---|---|---|
| Intertrap tunneling | ||
| qφa (meV) | 8.3 | 25.46 |
| w (cm) at 77 K | 4.70 × 10−7 | 3.724 × 10−7 |
| qφt(eV) at 77 K | 1.48 | 1.27 |
| Nt(cm−3) at 77 K | 9.62 × 1018 | 1.94 × 1019 |
| Variable range hopping | ||
| T0(K) | 8.45 × 103 | 7.44 × 105 |
| aB,ZnO(cm) | 2.67 × 10−7 | 1.04 × 10−7 |
| N(ε)(cm−3.eV−1) | 1.15 × 1021 | 2.2 × 1020 |
| Rm (cm) at 187.5 K | 2.677 × 10−7 | 3.2 × 10−7 |
| ∆W (meV) at 187.5 K | 10.78 | 33.07 |