Incorporating an Aromatic Cationic Spacer to Assemble 2D Polar Perovskite Crystals toward Self-Powered Detection of Quite Weak Polarized Light

Two-dimensional (2D) hybrid perovskites with intrinsic attributes of structural and optical anisotropy are holding a bright promise for polarization-sensitive photodetection. However, studies on self-powered detection to quite weak polarized light remain scarce in this 2D family. By incorporating an aromatic spacer into the 3D cubic prototype, we have successfully assembled a new 2D hybrid perovskite with a polar motif, (FPEA)(2)(MA)Pb2I7 (FMPI, where FPEA is 4-fluorophenethylammonium and MA is methylammonium). Its unique 2D quantum-well structure allows optical absorption dichroism with a large ratio of similar to 3.15, and the natural polarity results in a notable bulk photovoltaic effect. Further, centimeter-size crystals (10 x 10 x 3 mm(3)) of FMPI were facilely obtained by the temperature cooling method, and its crystal-based detectors enable excellent self-powered detection of quite weak polarized light, showing a notable polarization-sensitive ratio (similar to 1.5), extremely low detection limit (similar to 100 nW/cm(2)), and antifatigued stability. The alloyed aromatic cationic spacers facilitate the polarity and enhanced phase stability. This study paves a way for further exploration of new 2D perovskite candidates toward optoelectronic device applications.

Automated summary

This study successfully synthesized a new 2D hybrid perovskite with a polar motif by incorporating an aromatic spacer into the structure. The crystal-based detectors of this perovskite showed excellent self-powered detection performance for weak polarized light, indicating its potential applications in optoelectronic devices.