Polarization‐Sensitive Detector of Two‐Dimensional Multilayer Hybrid Perovskite Crystals Showing High Polarization Ratio to Weak Light

Abstract

Two-dimensional (2D) hybrid perovskite materials have been widely used for polarization-sensitive photodetection due to their fascinating optical and physical attributes. However, studies on those materials that enable strong polarized-light activities under a weak-light condition remain quite scarce. Here, by tailoring aromatic cation into 3D prototype, we have successfully obtained a new 2D hybrid perovskite, (FPEA) 2 (MA)Pb 2 Br 7 (1, where FPEA is 4-fluorophenethylammonium and MA is methylammonium). The alternative alignment of inorganic and organic structural components results in significant anisotropy, including optical absorption and electric conductivity. The coupling effect of these anisotropic properties in 1 gives rise to strong dichroic activities toward detecting polarized light. Especially, under weak light intensity (~330 nW/cm 2 ), it can still generate a large polarization ratio up to 1.35, which is even higher than those of some typical 2D materials (i. e., GeSe ~1.09). Besides, single crystal-based photodetector of 1 displays fascinating detecting performances, including large photocurrent on/off ratio (~10 4 ), fast response time (~154/182 μs) and excellent antifatigued stability. These findings disclose the potentials of 1 as a robust candidate for detecting weak polarized light, which has practical applications in the field of polarized optoelectronics.

Tailoring a Two-Dimensional Halide Perovskite Composed of the Secondary Amine Cation for Anisotropic X-ray Responses

“…By fitting the PL decay curve of 1 with a biexponential function, the average lifetime can be calculated to be 3.587 ns (Figure b). Figure c shows a comparison of the temperature-variable electrical conductivity measured along the different directions of 1 . The results indicate that the conductivity along the in-plane direction is higher than that of the out-of-plane direction since the organic cation layer inhibits the carrier transport and enhances resistance along the out-of-plane direction.…”

Recent Progress of Linear Polarization-Sensitive Photodetectors Based on Two-Dimensional Perovskites and Heterostructures

“…Besides, the photocurrent of the device remains essentially unchanged after 100 days, demonstrating its superior environmental stability. 80 Self-powered linear polarization-sensitive photodetectors can reduce energy consumption without requiring an external bias. Wang et al reported ferroelectric crystals of (isopentylammonium) 2 CsPb 2 Br 7 by a temperature-cooling method, and the device shows a stronger photoresponse.…”

“…The estimated responsivity (detectivity) is 8.7 mA/W (4.3 × 10 11 Jones). Besides, the photocurrent of the device remains essentially unchanged after 100 days, demonstrating its superior environmental stability …”