Exploring Lead‐Free Hybrid Double Perovskite Crystals of (BA)₂CsAgBiBr₇ with Large Mobility‐Lifetime Product toward X‐Ray Detection

Abstract

Halide double perovskites have recently bloomed as the green candidates for optoelectronic applications,such as Xray detection. Despite great efforts,the exploration of promising organic-inorganic hybrid double perovskites towardX-ray detection remains unsuccessful. Now,s ingle crystals of the lead-free hybrid double perovskite,( BA) 2 CsAgBiBr 7 (BA + is n-butylammonium), featuring the unique 2D multilayered quantum-confined motif,e nable quite large mt (mobilitylifetime) product up to 1.21 10 À3 cm 2 V À1 .T his figure-ofmerit realized in 2D hybrid double perovskites is unprecedented and comparable with that of CH 3 NH 3 PbI 3 wafers. (BA) 2 CsAgBiBr 7 crystals also exhibit other intriguing attributes for X-rayd etection, including high bulk resistivity,l ow density of defects and traps,a nd large X-raya ttenuation coefficient. Consequently,avertical-structure crystal device under X-rays ource yields as uperior sensitivity of 4.2 mCGy air À1 cm À2 .

Solution‐Grown Organic and Perovskite X‐Ray Detectors: A New Paradigm for the Direct Detection of Ionizing Radiation

“…The dynamic response of such detector to an X-rays from an Ag-targeted tube at 50 kVp, turned on and off is shown in Figure 8a. In the following years different kinds of PSCs, that is, hybrid [47,50,51,[87][88][89] and inorganic [52] lead-halide, lead-free [67,[90][91][92][93] perovskites have been demonstrated as active layer for X-and γ-rays and α-particles detectors. The top X-ray detection performance reported so far for a PSCs-based device was reported by Wei et al, [51] who demonstrated that a Cl − dopant compensation of p-type MAPbBr 3 SC results in a significant improvement of both bulk resistivity and hole mobility, enhancing thus the charge collection efficiency maintaining low dark currents.…”

Centimeter‐Sized Single Crystal of Two‐Dimensional Halide Perovskites Incorporating Straight‐Chain Symmetric Diammonium Ion for X‐Ray Detection

“…Fore xample,X ua nd co-workers fabricated a10mmsized 2D double perovskite single crystal based on the organic cations of BA + (C 4 H 9 NH 3 + )a nd achieved as ensitivity of 4.2 mCGy air À1 cm À2 . [17] Ji et al fabricated 3mms ized (BA) 2 EA 2 Pb 3 Br 10 (EA = HOC 2 H 4 NH 3 ) single crystals with an ultrahigh sensitivity of 6.8 10 3 mCGy air À1 cm À2 . [18] An alternative to the monoammonium cations reported so far is the employment of diammonium cations to form AA' nÀ1 M n X 3n+1 type 2D perovskites.T hese ditopic cations have two positive ends which act as bridges to electrostatically interact with the [MX 6 ] 2À slabs in the stacking direction.…”

Chiral Lead‐Free Hybrid Perovskites for Self‐Powered Circularly Polarized Light Detection

“…[7] Simultaneously, two-dimensional halide double perovskites with various compositions and performances have been rationally constructed by taking the advantage of the structure tunability. [8] Subsequently, high-performance X-ray detection and polarization-sensitive photodetection were achieved in (C 4 H 9 NH 3 ) 2 CsAgBiBr 7 [9] and (isopentylammonium) 2 CsAgBiBr 7 , [10] respectively. These prominent results enable lead-free double perovskites to be promising in optoelectronic application.…”