Hydration-mediated morphological and electronic tuning in layered double perovskites for p-type transparent conductors

The development of high-performance transparent conductors (TCs) is critical for advancing transparent electronics and optoelectronic devices. While n-type TCs are well established, the development of p-type TCs remains hindered by the limited availability of suitable materials. In this study, the layered double perovskite Cs 4 ZnBi 2 Cl 12 was synthesized as a promising p-type TC, which exhibits a wide direct band gap of 3.56 eV and intrinsic p-type conductivity. A hydration-mediated strategy was developed to trigger a near-spherical nanocrystal-to-nanorod transformation and modulate the electronic structure. First-principles calculations clarify that the lattice compressive strain induced by hydration significantly reduces the hole effective mass while increasing conductivity from 8.99 to 9.21 mS cm −1 , outperforming traditional p-type TCs, such as CuAlO 2 (3.4 mS cm −1 ) and SrCu 2 O 2 (0.48 mS cm −1 ). These findings not only provide experimental validation of the theoretical predictions regarding Cs 4 ZnBi 2 Cl 12 as a p-type TC but also establish a hydration strategy for optimizing the optical and electrical performance of layered double perovskites.