From 0D to 2D: Dimensional Tuning of Structural and Optoelectronic Properties of Pt Halide Perovskites

Platinum halide perovskites offer an environmentally friendly alternative to lead halide perovskites, demonstrating remarkable stability and optoelectronic properties. Here, the impact of dimensional engineering on optoelectronic properties of platinum halide perovskites, specifically 2D and 0D , has been explored. The 2D phase shows p‐type behavior and exhibits significant Stokes shift with broad emission around 850 nm. Strong short‐range electron–phonon (EP) coupling in the layered 2D structure results in self‐trapped excitonic emission as confirmed by low emission lifetime and Huang–Rhys factor of S = 16.8. In contrast, in this study, 0D exhibits n‐type behavior and no significant emissions under laser excitation, attributed to short‐range EP coupling leading to nonradiative recombination. Additionally, the mixed phase resulting from thermal decomposition of 2D behaves as a p‐type semiconductor. This observation aligns with first principles simulations, which suggest that low formation energy Pt interstitial defects in will tune the pristine n‐type into a slightly p‐type conductivity. These findings underscore the profound influence of dimensional engineering on the properties of platinum halide perovskites, offering valuable insights for developing stable and environmentally friendly perovskite materials for advanced optoelectronic applications.