One-step anti-solvent associated method for high performance two-dimensional perovskite photodetectors fabrication at low temperature

The two-dimensional (2D) organic-inorganic perovskite of unique optical properties and improved stability holds great potential in high-performance perovskite optoelectronic applications. However, a huge challenge to manufacture continuous thin films at large scale and low cost is still unresolved. Here, a facile method to fabricate high quality (PEA)2PbI4 thin films at low temperature in the air condition by one-step anti-solvent associated method was firstly proposed. The mechanism of nucleation sites formation and grain growth rates governed by the polarity and saturated vapor pressure of anti-solvents and annealing temperature was disclosed. By comparing different anti-solvents at various annealing temperatures, high quality thin films with the lowest annealing temperature of 80 ℃ were achieved by using toluene. A simple planar photodetector was configured, with the Responsivity (Rs) and Detectivity (D*) of 752 μA/W and 2.76×108 Jones with active area of 150 μm × 8000 μm, respectively, and the stability keeping 92% after 90 cycles under continuous light illumination and nearly 100% remaining after 10 weeks without additional encapsulation. This method offers a simple and low cost approach for manufacturing high quality 2D perovskite films and high performance photodetectors at low temperature for industrial applications.