Rational alloying of secondary and aromatic ammonium cations in a metal-halide perovskite toward crystal-array photodetection

Abstract

Two-dimensional (2D) hybrid perovskites with the Ruddlesden-Popper lattice (A') 2 (A) n−1 M n X 3n+1 are emerging as the promising optoelectronic candidates, both the inorganic and organic ingredients of which can be tailored to modulate the physical properties. Nevertheless, there is a scarcity of 2D multilayered motifs with the A-site large-size cations occupying perovskite cavities. Here, by rational mixedcation alloying, we present a new 2D hybrid perovskite, (4-TFBMA) 2 (DMA)Pb 2 I 7 (1), in which the secondary cation of CH 3 NH 2 CH 3 + (DMA) is located inside the perovskite cage while the aromatic 4-(trifluoromethyl)benzylammonium (4-TFBMA) cation acts as a spacer moiety. Benefiting from the quantum structure of alternating organic spacers and inorganic networks, crystal-array detectors of 1 show fascinating in-plane photodetection responses of large detectivity (~2.95 × 10 12 Jones) and responsivity (~1.97 A W −1 ), comparable to those of some inorganic 2D counterparts. In addition, a fast response rate (~264 µs) and a low dark current are also realized, related to the high crystalline quality and suppression of the hopping barrier due to the insulating organic spacing layers. This result sheds light on the further exploration of new 2D hybrid perovskites toward high-performance photodetector applications.

Asymmetric Diammonium Directed In-Plane Charge Transport Enhancement in Two-Dimensional Lead Bromide Perovskite for Weak-Light Detection

“…The inspiring photoconductivity behavior of DMPDPbBr 4 is indeed associated with the low bandgap, low defect densities, and low in-plane carrier effective masses in the “linear” direction. Notably, the optoelectronic performance of the DMPDPbBr 4 photodetector is comparable to the previously reported quasi-2D lead iodide and lead bromide perovskites, − indicating potential applications in optoelectronic devices.…”

Understanding the Origin of Light Intensity and Temperature Dependence of Photodetection Properties in a MAPbBr3 Single-Crystal-Based Photoconductor

“…Particularly, LHPs in the form of SCs reveal longer carrier diffusion length, lower trap density, high charge mobility, and improved environmental stability than their thin-film counterparts. Therefore, with the insignificant effect of grain boundary defects and surface defects, 2D and 3D LHP SCs hold huge promise for photodetection. − …”

Acquiring a Newly Tailored 2D Dion–Jacobson Hybrid Perovskite with Large Structural Distortion for Efficient Crystal Array Photodetector

“…Recently, it is noteworthy that the secondary cation of dimethylammonium (DMA + , r ∼ 278 pm) can serve as "perovskitizer" and locate inside the perovskite cavities of 2D RP-phase structures. [23][24][25] As far as we know, however, the multilayered DJ-type perovskites containing the secondary cations remain scarce, and the studies on their photoelectric properties are lacking. In this context, it is of great significance to exploit new DJ-type hybrid perovskites and promote their potential application toward optoelectronic devices.…”