Towards superior X-ray detection performance of two-dimensional halide perovskite crystals by adjusting the anisotropic transport behavior

Abstract

Two-dimensional (2D) organic-inorganic hybrid halide perovskites have recently attracted extensive attention for electronic and optoelectronic applications due to their tunable properties and superior stability compared with their three-dimensional (3D) counterparts....

A Three-Component Donor–Acceptor Hybrid Framework with Low-Power X-ray-Induced Photochromism

“…Photochromic materials usually exhibit reversible and visible color changes upon exposure to external light sources and have become an active research area in the past several years. Among them, considerable effort has been devoted to exploring ultraviolet (UV) or visible light-induced photophysical properties such as photomagnetism, photoconductance, and photoluminescence as well as applications in the field of erasable printing and smart windows. , However, the development of X-ray-induced photochromic materials is still in infancy. − At present, the scintillation counters, ionization gauges, and other devices have been developed for X-ray detection. − However, X-ray-sensitive materials used in these devices often require electronic attachments or tedious operations to process the signals. − Compared to commercial X-ray-sensitive materials, donor–acceptor (D–A) hybrid materials with organic and inorganic photoactive moieties fabricated at the molecular level make up an emerging class of photochromic materials that can be directly “visualized” by X-ray irradiation. − Although a few D–A hybrid materials with X-ray-induced photochromism (XIP) have been reported, most of them are produced in high-power environments, − and it is still rather rare for those with low-power XIP. , Accordingly, developing new radiosensitive D–A hybrid materials that can directly show a color change upon low-power irradiation with convenient operation is meaningful.…”

2D Organic–Inorganic Hybrid Perovskite Quantum Well Materials and Their Dramatical X-ray Optoelectronic Properties

“…The device based on the (BA) 2 CsPb 2 Br 7 crystal along the ab plane exhibited superior X-ray sensitivity of up to 13.26 mC Gyair −1 cm −2 at a relatively low electric field of 2.53 V mm −1 while displaying sensitivity lower than 20 µC Gy air −1 cm −2 along the c direction, even at a pretty high electric field of around 30 V mm −1 under the same irradiation of 40 kVp. By shortening the spacer cation from BA to i-BA, the degree of anisotropy in 2D perovskite crystals decreased, which resulted in lower ab plane X-ray sensitivity and higher c direction sensitivity compared to (BA) 2 CsPb 2 B r7based devices [56]. The 2D OIHP-like (NH 4 ) 3 Bi 2 I 9 shows remarkable anisotropy of charge transport as well.…”

Two-Dimensional Dion–Jacobson Perovskite (NH3C4H8NH3)CsPb2Br7 with High X-ray Sensitivity and Peak Discrimination of α-Particles

“…These bilayer organic spacer cations not only reduce the structural stability but also suppress the charge transport properties along the out-of-plane direction . Therefore, the carrier mobility along the out-of-plane direction in Ruddlesden–Popper perovskites could be enhanced by shortening the spacer cation . Subsequently, 2D Dion–Jacobson perovskites with the formula (NH 3 RNH 3 )­(A) n −1 B n X 3 n +1 were proposed, in which the diammonium cations (NH 3 + -R-NH 3 + ) adopted as the spacer cations contain two amino groups at both ends connecting to the inorganic layers by hydrogen bonds. , Compared to the well-studied Ruddlesden–Popper perovskites, the Dion–Jacobson perovskites exhibit an enhanced stability by eliminating the van der Waals gap. , Moreover, the Dion–Jacobson perovskites could also improve the transport properties along the out-of-plane direction because of the stronger interlayer interaction resulting from the reduced interlayer distance. , …”

“…(c) Summary of X-ray sensitivities of 2D perovskite crystals. The sphere and circle represent the carrier transport along out-of-plane and in-plane directions, respectively. ,,− (d) The long-term working stability of (BDA)­CsPb 2 Br 7 detector under the bias of 10 V.…”

“…18 Therefore, the carrier mobility along the out-of-plane direction in Ruddlesden−Popper perovskites could be enhanced by shortening the spacer cation. 19 Subsequently, 2D Dion− Jacobson perovskites with the formula (NH 3 RNH 3 )-(A) n−1 B n X 3n+1 were proposed, in which the diammonium cations (NH 3 + -R-NH 3 + ) adopted as the spacer cations contain two amino groups at both ends connecting to the inorganic layers by hydrogen bonds. 20,21 Compared to the well-studied Ruddlesden−Popper perovskites, the Dion−Jacobson perovskites exhibit an enhanced stability by eliminating the van der Waals gap.…”