Method | Film Thickness, d (nm) | Wavelength at maximum absorbance, ʎmax (nm) | Maximum absorbance | Optical direct band Gap Eg (eV) |
CBD | 72.67 | 390 | 0.20 | 3.12 |
Drop-Cast | 549 | 389 | 0.26 | 3.14 |
Dip-Coating | 281 | 387 | 0.40 | 3.16 |