Scalable fabrication of inch-sized FAPbI3 perovskite wafers for highly sensitive near-infrared photodetection

Perovskite wafers, with superior optoelectronic properties and stability, show great promise for photovoltaic and photoelectric applications. However, traditional solution growth methods struggle with crystallization control and phase purity, while solid-phase synthesis methods encounter high-density grain boundary traps. To tackle these issues, we devised a scalable method combining physical thermal field and chemical bonding to fabricate inch-sized FAPbI3 wafers, enabling efficient near-infrared photodetection. By integrating a 120 °C hot-pressing to stabilize the photoactive α phase and polyaniline polymer to conduct and passivate the grain boundaries, we obtained quasi-single crystal FAPbI3 wafers on a large scale. This approach overcomes the critical challenges of phase impurities and high-density defects, enhancing the phase stability of the FAPbI3 wafers. As a result, the FAPbI3 wafer-based photodetector exhibits an impressive external quantum efficiency of 312% at 854 nm near-infrared wavelength at 5 V bias, accompanied by a detectivity (D *) of 4.69 × 1014 Jones and rapid response time in microsecond-scale. This performance surpasses conventional solution-grown single crystals, providing a scalable foundation for future integrated perovskite optoelectronic devices.