μC Gyair Research Articles

Wearable Photoferroelectric Perovskite X‐Ray Detectors

AbstractHigh‐sensitivity wearable radiation detectors are essential for personnel protection in radiation environments such as defense, nuclear facilities, and medical fields. Traditional detectors using bulk crystals lack flexibility, and emerging perovskite films suffer from lead toxicity and poor charge transport. Herein, lead‐free photoferroelectric hybrid metal halide perovskite flexible membranes for wearable detectors are presented, offering superior X‐ray response with sensitivities up to 7872 ± 517 µC Gyair−1 cm−2 at 50 V bias and 394 ± 67 µC Gyair−1 cm−2 in a self‐driven mode, detection limit of lower than 77 nGyair s−1, and excellent imaging capabilities. This exceptional performance is attributed to the spontaneous polarization that promotes efficient charge transport. Additionally, they show remarkable radiation stability, long‐term air stability, mechanical fatigue resistance, and water stability. They also exhibit efficient energy response under the Compton effect and meet the angle response requirements of the International Electrotechnical Commission standard for direct‐reading personal dose equivalent meters, paving the way for their integration into flexible, wearable dosimeters. These advancements have the potential to drive the realization of the next generation of flexible wearable radiation detectors.

Perovskite Grown in Gallium Nitride Nanowire Matrix for Stable and High‐Efficiency X‐Ray Detection

AbstractHigh‐quality quasi‐2D perovskites in a GaN nano‐wire matrix are grown to build a 3D hetero‐structure for high‐performance X‐ray sensing. In the 3D hetero‐structure, GaN nano‐wire matrix serves as an n‐type charge collector that can rapidly extract carriers through the bulk film of the perovskite layer. Together with a p‐type top electrode, a p–i–n diode with the 3D hetero‐structure is built, that exhibits a rectified current–voltage characteristic. After analyzing the interface energy alignment, it is found that the fermi levels of the perovskite and GaN are aligned in the dark, and a quasi‐fermi level splits upon illumination, introducing a built‐in electrical field at the interface. As a result, strong photo‐induced current is observed from the diode without an external field. Finally, the 3D diode for X‐ray detection demonstration is used, revealing a sensitivity of 308.9 µC Gyair−1 cm−2 at an exceptionally low applied field of 0.125 V µm−1. The X‐ray‐induced signal from the 3D diode is stable after 155 cycles of X‐ray irradiation under a constant electric field. This demonstration informs a new 3D architecture for high‐performance X‐ray sensing, and it shows that GaN is a robust n‐type interface for perovskite optoelectronic devices.

Dense Perovskite Thick Film Enabled by Saturated Solution Filling for Sensitive X-ray Detection and Imaging.

Thick polycrystalline perovskite films synthesized by using solution processes show great potential in X-ray detection applications. However, due to the evaporation of the solvent, many pinholes and defects appear in the thick films, which deteriorate their optoelectronic properties and diminish their X-ray detection performance. Therefore, the preparation of large area and dense perovskite thick films is desired. Herein, we propose an effective strategy of filling the pores with a saturated precursor solution. By adding the saturated perovskite solution to the polycrystalline perovskite thick film, the original perovskite film will not be destroyed because of the solution-solute equilibrium relationship. Instead, it promotes in situ crystal growth within the thick film during the annealing process. The loosely packed grains in the original thick perovskite film are connected, and the pores and defects are partially filled and fixed. Finally, a much denser perovskite thick film with improved optoelectronic properties has been obtained. The optimized thick film exhibits an X-ray sensitivity of 1616.01 μC Gyair-1 cm-2 under an electric field of 44.44 V mm-1 and a low detection limit of 28.64 nGyair s-1 under an electric field of 22.22 V mm-1. These values exceed the 323.86 μC Gyair-1 cm-2 and 40.52 nGyair s-1 of the pristine perovskite thick film measured under the same conditions. The optimized thick film also shows promising working stability and X-ray imaging capability.

Inorganic Cs3Bi2I9 lead-free halide perovskite film for large-area X-ray detector via low-cost ambient spray coating

Lead-free Cs3Bi2I9 single crystals have been demonstrated to be promising materials for direct X-ray detectors with remarkable performance. However, their application for 2D X-ray imaging is hindered by their time-consuming preparation and limited crystal size. In this paper, a thick Cs3Bi2I9 perovskite film fabricated via facile spray coating at a low processing temperature, which increases the area of the photoactive film, reduces the processing time, decreases the energy budget and the production cost, and enhances the production yield due to high material utilization, has great potential for commercial applications. Careful control of the processing temperature and intervals during spray coating results in a dense and thick perovskite film with well-stacked perovskite domains. The compact perovskite film enhances the charge transport capability of the Cs3Bi2I9 perovskite film and reduces the dark current density of the X-ray detector. The resultant X-ray detector, prepared through a two-step spray coating process, exhibited a sensitivity of 127.23 μC Gyair−1 cm−2 and a detection limit of 7.4 μGyair s−1. In addition, the device delivers long-term stability with a consistent photoresponse when exposed to consecutive X-ray pulse irradiation.

Perovskite intermediate phase FAPbBr3·DMSO assisted in-situ growth of FAPbBr3 polycrystalline wafer for X-ray detection and imaging

Polycrystalline perovskite wafers featured in customizable in dimensions and thickness, represent a frontier in mass production of X-ray detectors. Nevertheless, inherent low crystallinity, elevated defect density, and grain boundaries in polycrystalline wafers typically impair the detection performance. Herein, a novel hot-pressing approach employing the perovskite intermediate phase FAPbBr3·DMSO was demonstrated to improve the quality and X-ray detection performance of polycrystalline perovskite wafers. The in-situ growth of FAPbBr3 wafers were promoted via dimethyl sulfoxide (DMSO) vapor released from the decomposition of FAPbBr3·DMSO phase during the hot-pressing process, resulting in compact morphology, large grain size, superior crystallinity and diminished defect density. The resulted wafers exhibit a high ion activation energy (Ea) of 0.45 eV and a substantial mobility-lifetime product (μτ) of 7.41 × 10−4 cm2 V−1. These advancements equip FAPbBr3 wafer-based detectors with remarkable sensitivity of 3694.6 μC Gyair−1 cm−2, low detection limit (LoD) of 43.8 nGyair s−1, and stable operational performance, comparable to that of single-crystal alternatives. Moreover, the detectors exhibit exceptional X-ray imaging capabilities with a spatial resolution of 4.41 lp mm−1. Thus, the thermally induced decomposition characteristic of perovskite intermediate phase presents a novel avenue for the amelioration of polycrystalline perovskite wafers, heralding a leap forward in X-ray detection performance.

High‐sensitive and fast MXene/silicon photodetector for single‐pixel X‐ray imaging

AbstractThe demand for high‐performance X‐ray detectors leads to material innovation for efficient photoelectric conversion and carrier transfer. However, current X‐ray detectors are often susceptible to chemical and irradiation instability, complex fabrication processes, hazardous components, and difficult compatibility. Here, we investigate a two‐dimensional (2D) material with a relatively low atomic number, Ti3C2Tx MXenes, and single crystal silicon for X‐ray detection and single‐pixel imaging (SPI). We fabricate a Ti3C2Tx MXene/Si X‐ray detector demonstrating remarkable optoelectronic performance. This detector exhibits a sensitivity of 1.2 × 107 μC Gyair−1 cm−2, a fast response speed with a rise time of 31 μs, and an incredibly low detection limit of 2.85 nGyair s−1. These superior performances are attributed to the unique charge coupling behavior under X‐ray irradiation via intrinsic polaron formation. The device remains stable even after 50 continuous hours of high‐dose X‐ray irradiation. Our device fabrication process is compatible with silicon‐based semiconductor technology. Our work suggests new directions for eco‐friendly X‐ray detectors and low‐radiation imaging system.image

High‐performance 110 kVp hard x‐ray detector based on all‐crystalline‐surface passivated perovskite single crystals

AbstractHalide perovskite single crystals (SCs) have attracted much attention for their application in high‐performance x‐ray detectors owing to their desirable properties, including low defect density, high mobility–lifetime product (μτ), and long carrier diffusion length. However, suppressing the inherent defects in perovskites and overcoming the ion migration primarily caused by these defects remains a challenge. This study proposes a facile process for dipping Cs0.05FA0.9MA0.05PbI3 SCs synthesized by a solution‐based inverse temperature crystallization method into a 2‐phenylethylammonium iodide (PEAI) solution to reduce the number of defects, inhibit ion migration, and increase x‐ray sensitivity. Compared to conventional spin coating, this simple dipping process forms a two‐dimensional PEA2PbI4 layer on all SC surfaces without further treatment, effectively passivating all surfaces of the inherently defective SCs and minimizing ion migration. As a result, the PEAI‐treated perovskite SC‐based x‐ray detector achieves a record x‐ray sensitivity of 1.3 × 105 μC Gyair−1 cm−2 with a bias voltage of 30 V at realistic clinical dose rates of 1–5 mGy s−1 (peak potential of 110 kVp), which is 6 times more sensitive than an untreated SC‐based detector and 3 orders of magnitude more sensitive than a commercial α‐Se‐based detector. Furthermore, the PEAI‐treated‐perovskite SC‐based x‐ray detector exhibits a low detection limit (73 nGy s−1), improved x‐ray response, and clear x‐ray images by a scanning method, highlighting the effectiveness of the PEAI dipping approach for fabricating next‐generation x‐ray detectors.image

Tailoring a Two-Dimensional Halide Perovskite Composed of the Secondary Amine Cation for Anisotropic X-ray Responses.

Two-dimensional (2D) metal-halide perovskites have shown broad application prospects in the field of optoelectronic detection. The presence of the natural quantum-well structure results in strong anisotropy of physical properties, while studies on anisotropic X-ray responses remain insufficient. Here, we present an intriguing anisotropy of X-ray-responsive behaviors in a 2D halide perovskite, (t-ACH)2(DMA)Pb2Br7 (1, where t-ACH is trans-4-(aminomethyl)cyclohexanecarboxylate and DMA is dimethylamine), in which the secondary amine DMA+ cation with a large ionic radius locates inside the perovskite cage to form inorganic frameworks. The alternative alignment of inorganic slabs and organic bilayers creates a typical quantum-well architecture, which accounts for the generation of photoelectronic anisotropy. High-quality crystals of 1 exhibit notable semiconducting properties with a large μτ product (1.9 × 10-4 cm2 V-1). Intriguingly, 1 has better X-ray detection sensitivity (∼569.9 μC Gyair-1 cm-2) along the in-plane direction, which is attributed to its excellent charge carrier transport performance in this direction. Conversely, the higher resistance stemming from the organic barrier results in a lower detection limit along the out-of-plane direction (∼78.1 nGyair s-1), much lower than the medical diagnostic criteria (∼5.5 μGyair s-1). This work might open up new possibilities for the creative use of hybrid perovskites in direct X-ray detection.

High-Performance Hard X-Ray Imaging Detector Using Facet-Dependent Bismuth Vanadate.

Bismuth vanadate (BiVO4) exhibits large absorption efficiency for hard X-rays, which endows it with a robust capacity to attenuate X-ray radiation across a broad energy range. The anisotropic properties of BiVO4 allow for the manipulation of their physical and chemical characteristics through crystallographic orientation and exposed facets. In this study, the issue of heavy recombination caused by sluggish electron transport in BiVO4 is successfully addressed by enhancing the abundance of the (040) crystal face ratio using a Co2+ crystal face exposure agent. The facet-dependent modifications exhibit excellent and balanced intrinsic charge transport properties, and finely optimize both the sensitivity and detection limit of BiVO4 X-ray detectors. As a result, ultra-stable BiVO4 metal oxide X-ray detectors demonstrate a high sensitivity of 3164 µC Gyair -1 cm-2 and a low detection limit of 20.76 nGyair s-1 under 110 kVp hard X-rays, establishing a new benchmark for X-ray detectors based on polycrystalline Bi-halides and metal oxides. These findings highlight the significance of crystal orientation in optimizing materials for X-ray detection, setting a new sensitivity record for X-ray detectors based on polycrystalline Bi-halides and metal oxides, which paves the way for the development of advanced, low-dose, and highly stable imaging systems specifically for hard X-rays.

Ligand‐Assisted Growth of 2D Perovskite Single Crystal for Highly Sensitive X‐Ray Detectors

AbstractThe emerging 2D layered perovskites have promising optoelectronic properties, good intrinsic stability and reduced ion migration, making them effective for detecting X‐ray radiation. However, their application is constrained by poor out‐of‐plane carrier transport. In this study, inch‐sized high‐quality CsPb2Br5 layered single crystals (SCs) are developed using an organic ligand‐assisted solution process. By modifying the surface energy, the anisotropy of crystal growth is conquered, resulting in CsPb2Br5 SCs with sufficient thickness for X‐ray detection. Importantly, this modification significantly enhanced the crystal quality as the grown CsPb2Br5 SCs exhibited longer photoluminescence lifetime and smaller trap density. Notably, the CsPb2Br5 SCs demonstrate unprecedented out‐of‐plane carrier transport, achieving a high carrier mobility‐lifetime product of 2.53 × 10−2 cm2V−1. This can be attributed to the small interlayer distance and the strong interlayer force of Cs─Br bonding. Furthermore, CsPb2Br5 SCs possess other intriguing attributes for X‐ray detection, including high bulk resistivity and outstanding thermal stability. These advantageous properties enable high‐performance vertical‐structure X‐ray detection with a superior sensitivity of up to 8865.6 µC Gyair−1cm−2 and a low detectable dose rate of 12.7 nGyairs−1. Additionally, CsPb2Br5 SCs exhibit high spatial resolution in X‐ray imaging and exceptional thermal stability, making them promising candidates for nondestructive determination.

Ga2O3 Photon‐Controlled Diode for Sensitive DUV/X‐Ray Detection and High‐Resolution Array Imaging Application

AbstractSensitive high‐energy photon detection from UV to X‐ray and high‐resolution array imaging are critical for medical diagnosis, space exploration, and scientific research. The key challenges for high‐performance photodetector and imaging arrays are the effective material and device design strategies for the miniaturization and integration of the device. Here, photon‐controlled diodes (i.e., the detector has rectifying characteristics only under light irradiation) are proposed for high‐resolution and anti‐crosstalk array imaging applications without integrating the switching element. Based on ultra‐wide bandgap semiconductor Ga2O3, the sensitive DUV/X‐ray photon‐controlled diodes are realized by the design of high‐resistance Ga2O3 film and high‐barrier contact. The device exhibits remarkable detection performance, including high photo‐responsivity (168 A W−1) and specific detectivity (1.45 × 1015 Jones) under DUV illumination, as well as a high sensitivity (1.23 × 105 µC Gyair−1 cm−2) under X‐ray light. Moreover, the low dark current and excellent rectification characteristics are obtained. Furthermore, its potential for high‐density and anti‐crosstalk array imaging applications is verified. These results not only bring forth new insights in the implementation of high‐performance DUV/X‐ray photodetector, but also pave a feasible way to realize high pixel density detector array through the simplified fabrication process for high‐resolution imaging applications.

Sensitive and Low-Noise Perovskite Nanocrystal-Organic Bulk Heterostructure X-ray Detectors Enabled by Sodium Bromide-Assisted In Situ Reparation.

Perovskite nanocrystals (PNCs) offer unique advantages in large-area and thick-film deposition for X-ray detection applications due to the decoupling of the crystallization of perovskite from film formation, as well as their low-temperature and scalable deposition methods. However, the partial detachment of long-chain ligands in PNCs during the purification process would lead to the exposure of surface defects, making it challenging to ensure efficient charge carrier extraction and stable X-ray detection. In this study, we propose a beneficial strategy that involves the in situ reparation of these exposed defects with sodium bromide (NaBr) during the purification process to construct CsPbBr3 PNC-organic bulk heterostructure X-ray detectors. The NaBr-passivated PNCs exhibit stronger photoluminescence intensity and lower trap density in films compared to those of the control samples, confirming the effective passivation of halide vacancy defects. Furthermore, the NiOx hole transport layer with remarkable electron blocking capability is introduced to further suppress the dark current of the devices. Consequently, the optimal devices exhibit a large sensitivity of 4237 μC Gyair-1 cm-2 and a low dark current density of 10 nA cm-2, as well as improved operational stability, which allows for high-contrast and low-dose X-ray imaging applications.

"One-Click Restart" Recycling of Metal-Free Perovskite X-Ray Detectors.

Halide perovskites have shown great potential in X-ray detection due to outstanding optoelectronic properties. However, finding a cost-effective and environmentally sustainable method for handling end-of-life devices has remained challenging. Here, a "One-Click Restart" eco-friendly recycling strategy is introduced for end-of-life perovskite X-ray detectors. This method, utilizing water, allows for the recapture and reuse of both perovskite and conductor materials. The process is straightforward and environmentally friendly, eliminating the need for further chemical treatment, purification, additional additives or catalysts, and complex equipment. A sustainable device cycle is developed by reconstructing flexible perovskite membranes for wearable electronics from recycled materials. Large-scale, flexible membranes made from metal-free perovskite DABCO-N2H5-I3 (DABCO = N-N'-diazabicyclo[2.2.2]octonium) achieve remarkably impressive average sensitivity of 6204 ± 268 µC Gyair -1cm-2 and a low detection limit of 102.3 nGyair s-1, which makes highly effective for X-ray imaging. The sensitivity of recycled flexible devices not only matches that of single-crystal devices made with fresh materials but also ranks as the highest among all metal-free perovskite X-ray detectors. "One-Click Restart" applies to scalable flexible devices derived from aged single-crystal counterparts, offering significant cost, time, and energy savings compared to their single-crystal equivalents. Such advantages significantly boost future market competitiveness.

Highly Stable and Sensitive (PEA)2PbBr4/CsPbBr3 Single‐Crystal Heterojunction X‐Ray Detector with Ultra‐Low Detection Limit

AbstractMetal halide perovskite (MHP) single crystals have shown great potential for high‐performance X‐ray detection due to their excellent carrier transport properties, tunable optical bandgap, and low‐temperature fabrication process. However, 3D perovskite single crystals suffer from severe ion migration, limiting the stability and sensitivity of X‐ray detectors. Herein, a lowing temperature crystallization (LTC) method for liquid‐phase epitaxial growth of 2D (PEA)2PbBr4 single‐crystal (SC) film on 3D CsPbBr3 substrate is demonstratedand a 2D/3D (PEA)2PbBr4/CsPbBr3 SC heterojunction is successfully constructed. The epitaxial (PEA)2PbBr4 layer shows a pronounced passivation effect on CsPbBr3 SC with a low trap density of 2.27 × 1010 cm−3. As such, the prepared 2D/3D heterojunction X‐ray detector achieves a record‐low detectable dose rate of 3.05 nGyair s−1 and high sensitivity of 34496 µC Gyair−1 cm−2 in 120 keV hard X‐ray detection, with a largely suppressed dark current drift of 2.49 × 10−4 nA cm−1 s−1 V−1. In addition, the heterojunction detector exhibits a self‐driven sensitivity of 44 µC Gyair−1 cm−2 due to its built‐in electric field. This work provides a simple strategy to controllable construct 2D/3D MHP SC heterojunction with excellent optoelectronic characteristic, which is conducive to promoting the development of MHP SC X‐ray detectors and other optoelectronic devices.

Interface Engineering of Substrate-Integrated Single-Crystal Perovskite Wafers for Sensitive X-Ray Detection.

Metal halide perovskite single crystals are emerging candidates for X-ray detection, however, it is challenging for growth of thickness-controlled single-crystal wafer on commercial backplanes, limiting their practical imaging application. Herein, integration of micrometer-thick methylammonium lead triiodide (MAPbI3) single-crystal wafer on indium tin oxide (ITO) substrates by methylamine (MA)-induced interface recrystallization is reported. Through selection of hole transport material with rich functional group, intimate interface contact with low trap density can be achieved, leading to superior carrier transport properties and homogeneous photoresponse. The as-fabricated X-ray detectors exhibit high sensitivity of 1.4×104 µC Gyair -1 cm-2 and low detection limit of 177 nGyair s-1, which are comparable to previous reports based on free-standing MAPbI3 bulk crystals. This work provides a feasible strategy for constructing substrate-integrated single-crystal perovskite wafers with controlled thickness, which may promote practical imaging application of perovskite X-ray detectors.

Aminoazanium of A-site Cations in Metal-Free Halide Perovskite Single Crystals to Reduce Thermal Expansion for Efficient X-ray Detection.

Metal-free perovskites (MFPs) have recently become a newcomer in X-ray detection due to their flexibility and low toxicity characteristics. However, their photoelectronic properties and stability should be further improved mainly through materials design. Here, the aminoazanium of DABCO2+ was developed for the preparation of NDABCO-NH4Br3 (NDABCO = N-amino-N'-diazabicyclo[2.2.2]octonium) single crystals (SCs), and its physical properties, intermolecular interactions, and device performance were systematically explored. Notably, NDABCO-NH4Br3 can achieve improved stability by enlarging defect formation energy and inducing abundant intermolecular forces. Moreover, the slight lattice distortion could ensure the weakening electron-phonon coupling for improving carrier transport. In particular, the slight lattice distortion after the long-chain NDABCO2+ introduction could retard thermal expansion for the preparation of high-quality crystals. Finally, the corresponding X-ray detector delivered a moderate sensitivity of 623.3 μC Gyair-1 cm-2. This work provides a novel strategy through rationally designed organic cations to balance the material stability and device performance.

Out‐Of‐Phase Articulation Strategy of CsPbBr3/CsPb2Br5 Perovskite for High Sensitivity X‐Ray Detection

AbstractPolycrystalline CsPbBr3 perovskite materials exhibit exemplary stability, and desirable optoelectronic characteristics are promising for direct X‐ray detection. In this study, polycrystalline 2D phase of CsPb2Br5 hinged on CsPbBr3 is investigated for X‐ray array detector. The incorporation of CsPb2Br5 will modify the carrier transport environment, acting as an amplification factor that significantly enhances carrier mobility and response sensitivity. Finally, the devices demonstrates excellent performance growth. Carrier mobility of CsPbBr3 is improved by a significant 2 orders of magnitude, leading to the sensitivity increased from 2.64 × 104 to 2.58 × 105 µC Gyair−1 cm−2 at a bias voltage of 25 V mm−1. Even at a low bias voltage of 2 V mm−1, still got the value of 3.075 × 103 µC Gyair−1 cm−2, accompanied by a notable increase in the minimum detection limit of 127.9 nGyair s−1 at 0.5 V. Furthermore, a high modulation transfer function (MTF) of 1.57 lp mm−1 is obtained, and achieved a clear and high contrast X‐ray imaging with 64 × 64 TFT board. The perovskite exhibits outstanding light stability (RH ≈ 70 ± 5%) in the atmosphere following the introduction of 2D phase. This excellent carrier transport effect and good long‐term stability present significant commercial potential.

Spacer Conformation Induced Multiple Hydrogen Bonds in 2D Perovskite toward Highly Efficient Optoelectronic Devices.

Two-dimensional (2D) Dion-Jacobson (DJ) perovskites typically outperform Ruddlesden-Popper (RP) analogs in terms of photodetection (PD). However, the mechanism behind this enhanced performance remains elusive. Theoretical calculations for elucidating interlayer spacer conformation-induced multiple hydrogen bonds in 2D perovskite are presented, along with the synthesis of DPAPbBr4 (DPB) single crystals (SCs) and their PD properties under X-ray/ultraviolet (UV) excitation. The high-quality DPB SC enhances PD with exceptional photoresponse attributes, including a high on/off ratio (4.89×104), high responsivity (2.44 AW⁻1), along with large dynamic linear range (154 dB) and low detection limit (7.1 nWcm⁻2), which are currently the best results among 2D perovskite SC detectors, respectively. Importantly, high-resolution images are obtained under UV illumination with weak light levels. The SC X-ray detector exhibits a high sensitivity of 663 µC Gyair⁻1 cm-2 at 10 V and a detection limit of 1.44 µGyair s⁻1. This study explores 2D DJ perovskites for efficient and innovative optoelectronic applications.

Biocompatible Metal-Free Perovskite Membranes for Wearable X-ray Detectors.

Halide perovskites are emerging as promising materials for X-ray detection owing to their compatibility with flexible fabrication, cost-effective solution processing, and exceptional carrier transport behaviors. However, the challenge of removing lead from high-performing perovskites, crucial for wearable electronics, while retaining their superior performance, persists. Here, we present for the first time a highly sensitive and robust flexible X-ray detector utilizing a biocompatible, metal-free perovskite, MDABCO-NH4I3 (MDABCO = methyl-N'-diazabicyclo[2.2.2]octonium). This wearable X-ray detector, based on a MDABCO-NH4I3 thick membrane, exhibits remarkable properties including a large resistivity of 1.13 × 1011 Ω cm, a high mobility-lifetime product (μ-τ) of 1.64 × 10-4 cm2 V-1, and spin Seebeck effect coefficient of 1.9 nV K-1. We achieve a high sensitivity of 6521.6 ± 700 μC Gyair-1 cm-2 and a low detection limit of 77 nGyair s-1, ranking among the highest for biocompatible X-ray detectors. Additionally, the device exhibits effective X-ray imaging at a low dose rate of 1.87 μGyair s-1, which is approximately one-third of the dose rate used in regular medical diagnostics. Crucially, both the MDABCO-NH4I3 thick membrane and the device showcase excellent mechanical robustness. These attributes render the flexible MDABCO-NH4I3 thick membranes highly competitive for next-generation, high-performance, wearable X-ray detection applications.

Low‐Dose and Stable X‐Ray Imaging Enabled by Low‐Dimensional Dion‐Jacobson Perovskites

AbstractMetal halide perovskites have emerged as highly promising candidates for next‐generation X‐ray detectors due to their facile and low‐cost processability, high attenuation coefficient, and tunable optoelectrical properties. In this work, quasi‐2D Dion‐Jacobson (DJ) perovskites are introduced in a flat panel X‐ray imager (FPXI) for X‐ray imaging. This study demonstrates that the diammonium interlayers in DJ perovskites play a key role in enhancing structural stability, suppressing ion migration, and improving charge transport. As a result, DJ perovskite‐based X‐ray FPXIs achieve a sensitivity of 18000 µC Gyair−1 cm−2, a low detection limit of 5.7 nGyair s−1, representing performance comparable to that of state‐of‐the‐art 3D perovskite FPXIs. Thanks to the decrease in the signal crosstalk effect of the FPXIs, a high spatial resolution of 0.54 line‐pair‐per‐pixel is achieved, which is higher than that of 3D perovskite FPXIs. Remarkably, high‐quality X‐ray imaging is achieved at a total dose of 20 µGyair, which is only 1/5 of the dose typically used in commercial equipment. This work not only provides valuable insights and guidance for the fabrication of 2D DJ perovskite X‐ray detectors but also lays the groundwork for the adoption of high‐performance, stable DJ perovskite imagers as novel flat‐panel X‐ray detectors.