Releasable Water Charge‐Trapping and Water‐Resistant Photodetection using 1D Perovskitoid Hydrate Single Crystal

Abstract

Hydrates of hybrid organic–inorganic perovskites have been discovered with MAPbI3 and are proved to be unstable in atmosphere. However, the influence of water molecules on the performance of optoelectronic devices is still not fully understood. Here, using a dication, 2‐(dimethylamino) ethylamine (DMEN2+), a stable quasi‐1D perovskitoid hydrate single crystal is designed and successfully synthesized, which is formulated as DMENPb2I6·H2O. In this design, both corner‐sharing and edge‐sharing connectivity are adopted, and water molecules are connected with the crystal through hydrogen bonding. It is discovered that such water sites distributed along the inorganic chains function both as charge traps and as releasable charge stocks. Optical excitation that overcomes the potential wells formed on these water sites may release these stocked charges and facilitate enhanced transportable charge density. Meanwhile, exciton diffusion and charge transport are strongly confined in the 1D transport channels. Above mechanisms are verified both by the transient absorption spectroscopy and by the photodetection performance. This introduces a new design strategy with a trapping–stock–releasing–transport roadmap for perovskitoid materials. Excellent water resistance endows this material with more advantages in the development of a new generation of optoelectronic devices.

Enhanced photoelectric performance in Cu–Bi double halide perovskite single crystals

“…Compared to the 0D one, fewer crystallized water molecules observed in the (CHDA) 2 CuBiI 8 Á0.5H 2 O provide potential benefits for reducing trapping centres and enhancing carrier collection efficiency. 44 XRD patterns were measured from bulk crystals to examine their preferential orientation. Fig.…”

Two-Dimensional Hybrid Perovskitoid Micro/nanosheets: Colorful Ultralong Phosphorescence, Delayed Fluorescence, and Anisotropic Optical Waveguide

“…As one of the most promising photoactive materials, organic metal hybrid perovskites , or perovskitoids , (OMHPs) have exhibited a wide range of applications, such as solar cells, photodetectors, light-emitting diodes (LEDs), and lasers. − OMHPs feature a general chemical formula of ABX 3 , where A is an organic cation and B is a metal cation, and X refers to a halide anion (Cl – , Br – , I – or a mixture thereof) . The dimensional diversity and structural flexibility enable OMHPs micro/nanostructures to demonstrate interesting photonic behaviors .…”

Combining π-Conjugation and Cation−π Interaction for Water-Stable and Photoconductive One-Dimensional Hybrid Lead Bromide

“…The results are similar to the recently reported data for [(CH 3 ) 2 NH-(CH 2 ) 2 NH 3 ]Pb 2 I 6 •H 2 O, where the water of crystallization acts as both charge-trapping and charge reservoir centers. 40 Though the values of responsivity and detectivity are lower than those of a typical good photodetector, the obtained numbers are remarkable for a hybrid perovskite system that is completely water-stable. The photoresponse of a (4,4′-VDP)Pb 2 Br 6 single crystal exhibits a sharp switching during the on−off cycles without any quenching of photocurrent over a long period of time, suggesting the photostability of (4,4′-VDP)Pb 2 Br 6 under the applied bias (Figure 5c and Figure S12).…”

“…From the photoresponse data of (4,4′-VDP)Pb 2 Br 6 , a peak responsivity of 5 mA/W and a peak detectivity of 0.8 × 10 9 Jones are obtained. The results are similar to the recently reported data for [(CH 3 ) 2 NH(CH 2 ) 2 NH 3 ]Pb 2 I 6 ·H 2 O, where the water of crystallization acts as both charge-trapping and charge reservoir centers . Though the values of responsivity and detectivity are lower than those of a typical good photodetector, the obtained numbers are remarkable for a hybrid perovskite system that is completely water-stable.…”