Synergistic Control of Organic Lead Chloride Perovskite Crystallization through the Precursor and Growth Substrate for High-Performance and Stable Transparent Optoelectronics

Transparent optoelectronics are crucial in modern applications, advancing display technologies in smartphones and smart windows, and supporting high-speed communication systems and advanced sensors. CH₃NH₃PbCl₃ (MAPbCl₃) has garnered significant attention due to its ideal optical bandgap and outstanding optoelectronic performance. However, the fabrication of high-quality MAPbCl₃ thin films faces significant challenges, primarily due to the uncontrolled nucleation process, which results in nonuniform crystallization, poor surface coverage with numerous voids, and high roughness. In this work, we utilized methylammonium acetate (MAAc) as a solvent to form the MAPbCl₃ precursor. This approach not only enables the air-processed fabrication of MAPbCl₃ but also produces uniform colloidal particles, which are beneficial for the formation of compact thin films. We investigated the influence of common hole transport layers (NiO_x, PTAA, PEDOT:PSS) on the crystallization of MAPbCl₃ films. By synergistically controlling both the precursor and the growth substrate, we significantly improved the quality of the MAPbCl₃ film. The resulting photodiode, based on the high-quality MAPbCl₃ film, demonstrated potential for transparent photovoltaics and exhibited excellent performance as a photodetector. Specifically, it achieved a responsivity R of 162.5 mA/W and a detectivity (D*) of 8.9 × 10¹² Jones at 390 nm, with high response speed (1.37 μs rise time and 1.68 μs fall time) even under self-powered operation (0 V). Furthermore, the device was successfully integrated into an optical communication system. These results highlight the great potential of high-quality MAPbCl₃ devices in transparent optoelectronic applications.