Solution-phase, template-free synthesis of PbI2 and MAPbI3 nano/microtubes for high-sensitivity photodetectors

Abstract

Organic–inorganic hybrid perovskite materials with exotic semiconducting properties have become inevitable candidates for next-generation electronic devices. Very recently, a low dimensional nanostructure of the perovskite materials has attracted the scientific community due to its enhanced performance in optoelectronics as compared to its bulk counterparts. Herein, a facile method was developed for the scalable, room-temperature synthesis of CH₃NH₃PbI₃ (MAPbI₃) nano/microtubes by direct conversion of lead iodide (PbI₂) microtubes through a solution-phase method. At first, the PbI₂ microtubes were synthesized by the anti-solvent crystallization process and subsequently converted to CH₃NH₃PbI₃ nano/microtubes by the addition of CH₃NH₃I (MAI) precursor directly in the solution phase. The corresponding photodetectors (PDs) in the lateral metal–semiconductor–metal (MSM) configuration of the PbI₂ microtubes and MAPbI₃ nano/microtubes on glass substrates were investigated systematically. Compared to the PbI₂ based PDs (557 mA W⁻¹, 3.65 × 10¹² Jones, 0.251 s/0.252 s), the MAPbI₃ based PDs exhibit higher photoresponsivity, specific detectivity, and faster response time (25 A W⁻¹, 9.9 × 10¹³ Jones, 49 ms/20 ms) under irradiation with 4.6 μW cm⁻² intensity light of the 532 nm laser at a bias of 5 V. The proposed method is a low-temperature process, easy to apply in large scale synthesis, and finds potential applications in optoelectronic devices.