Table 2.
Summary of crystal size, determined with XRD, normalized elemental composition (Cu:S for SEM, Cu:In:S for STEM measurements) and band gap of the CuInS2 films synthesized with l-cysteine at different reaction temperatures for 18 h. Values of film_120 °C are not included in the average value in the last row.
| Crystal Size XRD (nm) | EDX SEM Cu:S (Normalized) | EDX TEM Cu:In:S (Normalized) | Band Gap UV-Vis (eV) | |
|---|---|---|---|---|
| film_120 °C | --- | 1.0:3.9 | --- | 1.51 |
| film_140 °C | 7.9 ± 0.5 | 1.0:1.9 | 1.0:1.1:2.2 | 1.52 |
| film_S [32] | 9.4 ± 0.6 | 1.0:2.5 | 1.0:1.0:2.1 | 1.47 |
| film_160 °C | 9.2 ± 1.0 | 1.0:1.7 | --- | 1.54 |
| film_180 °C | 11.4 ± 1.0 | 1.0:1.6 | --- | 1.55 |
| film_190 °C | 9.8 ± 0.6 | 1.0:1.4 | 1.0:1.0:1.9 | 1.54 |
| Ø | 9.5 ± 1.1 | 1.0:1.8 ± 0.4 | --- | 1.52 ± 0.03 |