Quasi-2D Perovskite Crystalline Layers for Printable Direct Conversion X-Ray Imaging

Polycrystalline perovskite film-based X-ray detector is an appealing technology for assembling large scale imager by printing methods. However, thick crystalline layer without trap and solvent residual is challenging to fabricate. Here, the authors report a solution method to produce high quality quasi-2D perovskite crystalline layers and detectors that are suitable for X-ray imaging. By introducing n-butylamine iodide into methylammonium lead iodide precursor and coating at elevated temperatures, compact and crystalline layers with exceptional uniformity are obtained on both rigid and flexible substrates. Photodiodes built with the quasi-2D layers exhibit a low dark current and stable operation under constant electrical field over 96 h in dark, and over 15 h under X-ray irradiation. The detector responds sensitively under X-ray, delivering a high sensitivity of 1214 mu C Gy(air)(-1) cm(-2) and a sensitivity gain is observed when operated under higher fields. Finally, high resolution images are demonstrated using a single pixel device that can resolve 80-200 mu m features. This work paves the path for printable direct conversion X-ray imager development.

Automated summary

The authors report a solution method to produce high-quality quasi-2D perovskite crystalline layers and detectors suitable for X-ray imaging. The photodiodes built with the quasi-2D layers exhibit low dark current and stable operation, and the detector shows a high sensitivity to X-ray. High-resolution images can be obtained using a single pixel device.