Table 1.
Summary of structural and functional differences between 3D, 2D, and quasi-2D halide perovskites
| Feature | 3D perovskite | 2D perovskite | Quasi-2D perovskite |
|---|---|---|---|
| Formula | ABX3 | R2An−1BnX3n+1 | R2An−1BnX3n+1 |
| Dimensionality | Isotropic 3D network | Layered (Single inorganic sheet) | Hybrid (2–5 inorganic layers) |
| Bandgap | 1.5–2.0 eV | > 2.0 eV | 1.8–2.2 eV |
| Stability | Low (moisture/ heat sensitive) | High (hydrophobic spacers) | Moderate to high |
| Charge transport | Excellent (all directions) | Poor (out-of-plane) | Improved (in-plane delocalization) |
| Environmental Stability | Poor (moisture-sensitive) | High (hydrophobic layers) | Moderate to high |
| Ion migration control | Weak (fast ion mobility) | Strong (confined migration) | Controlled (n-dependent) |