PbI₂‐DMSO Assisted In Situ Growth of Perovskite Wafers for Sensitive Direct X‐Ray Detection

Abstract

Although perovskite wafers with a scalable size and thickness are suitable for direct X‐ray detection, polycrystalline perovskite wafers have drawbacks such as the high defect density, defective grain boundaries, and low crystallinity. Herein, PbI2‐DMSO powders are introduced into the MAPbI3 wafer to facilitate crystal growth. The PbI2 powders absorb a certain amount of DMSO to form the PbI2‐DMSO powders and PbI2‐DMSO is converted back into PbI2 under heating while releasing DMSO vapor. During isostatic pressing of the MAPbI3 wafer with the PbI2‐DMSO solid additive, the released DMSO vapor facilitates in situ growth in the MAPbI3 wafer with enhanced crystallinity and reduced defect density. A dense and compact MAPbI3 wafer with a high mobility‐lifetime (µτ) product of 8.70 × 10−4 cm2 V−1 is produced. The MAPbI3‐based direct X‐ray detector fabricated for demonstration shows a high sensitivity of 1.58 × 104 µC Gyair−1 cm−2 and a low detection limit of 410 nGyair s−1.

Chirality Inducing Polar Photovoltage in a 2D Lead-Free Double Perovskite toward Self-Powered X-ray Detection

“…X-ray detectors play indispensable roles in many important sectors, including medical diagnostics, nondestructive production tests, security screenings, scientific research. − Therefore, exploring novel materials for high-performance X-ray detectors is an ongoing research hotspot worldwide. In the past decade, lead halide perovskites (LHPs) have emerged as a class of star materials for X-ray detection because of their easy synthesis, efficient X-ray attenuation as well as outstanding optoelectronic properties. − Through the unremitting efforts of researchers, a remarkable sensitivity ( S ) of 2.2 × 10 8 μC Gy –1 cm –2 and an ultralow detection limit (LoD) of 0.1 nGy s –1 have been achieved in (CH 3 NH 3 )­PbI 3 -based detectors, greatly exceeding those traditional X-ray detection semiconductors. , However, these detectors almost all run under a high external electric field, which not only causes operational instability originated from serious ion migration but also results in bulky overall circuit and high energy consumption. ,, Thus, developing self-powered devices that can work without external bias has gained growing interest in X-ray detection. Conventionally, constructing p - n heterojunctions can form built-in electric field to separate and transport photogenerated carriers, thus allowing them to be self-powered. − But this approach suffers from a complicated fabrication process and interface engineering.…”

Supple Formamidinium-Based Low-Dimension Perovskite Derivative for Sensitive and Ultrastable X-ray Detection

“…35 And the plastic deformation of the supple δ-FAPbI 3 powder during the pressing process is more conducive to forming compact wafers with less porosity and low residual stress. Additionally, high-quality δ-FAPbI 3 wafers can be fabricated using a simple compressing process, avoiding the high-temperature treatment widely used in other works, 13,15,36 implying a great competitiveness in commercial applications. Ionic Migration in the Wafers.…”

Weak X‐Ray to Visible Lights Detection Enabled by a 2D Multilayered Lead Iodide Perovskite with Iodine‐Substituted Spacer

“…[ 31 ] The realization of the low detection limit in our device is mainly due to the extremely low dark current and inhibited ion migration. The dark current drift ( I drift ) is another important parameter for assessing the operational stability of detectors, which can be determined by the following equation [ 36 ] $$$$\begin{equation}{I}_{{\rm{drift}}} = \left( {{I}_{{t}} - {I}_0} \right) / \left( {E \times S \times t} \right)\end{equation}$$$$where the I t and I 0 are, respectively, dark current at time t and 0, E represents the electric field, and S is the device area. As presented in Figure S18 (Supporting Information), I drift of 1 device is calculated to be 7.76 × 10 −6 nA cm −1 s −1 V −1 , which reveals its excellent operational stability.…”

“…[31] The realization of the low detection limit in our device is mainly due to the extremely low dark current and inhibited ion migration. The dark current drift (I drift ) is another important parameter for assessing the operational stability of detectors, which can be determined by the following equation [36] I drift = (…”