Solvent-hydrolysis-driven engineering of ordered single quantum well 2D perovskites

Single quantum well (single-QW) two-dimensional (2D) perovskites are set to transform optoelectronic devices due to their stability and superior properties. However, solution-processed 2D perovskites often form disordered multiple-QW structures, leading to inconsistent performance. Here, we present a solvent-hydrolysis-driven method for controlling crystallization kinetics, resulting in highly ordered single-QW 2D perovskite films. Dimethylamine (DMA), formed from the hydrolysis of N , N -dimethylformamide (DMF), acts as a key mediator, preventing cluster aggregation and ensuring uniform colloidal distribution. This process avoids a heterogeneous intermediate phase, thereby fostering the formation of a homogeneous (DMA,MA)PbI 3 phase, which is crucial for the development of single-QW films. The resulting photodetector demonstrates outstanding performance, with a responsivity of 1153 mA/W and a detectivity of 6.98 × 10 12 Jones, along with excellent photostability under ambient conditions. These attributes make it ideal for photoelectric imaging sensors and large-scale integration. Our findings provide a scalable, solution-processed strategy for high-performance 2D perovskite materials, opening up new possibilities for advanced optoelectronic applications.