Perovskite-Based X-ray Detectors

Abstract

X-ray detection has widespread applications in medical diagnosis, non-destructive industrial radiography and safety inspection, and especially, medical diagnosis realized by medical X-ray detectors is presenting an increasing demand. Perovskite materials are excellent candidates for high-energy radiation detection based on their promising material properties such as excellent carrier transport capability and high effective atomic number. In this review paper, we introduce X-ray detectors using all kinds of halide perovskite materials along with various crystal structures and discuss their device performance in detail. Single-crystal perovskite was first fabricated as an active material for X-ray detectors, having excellent performance under X-ray illumination due to its superior photoelectric properties of X-ray attenuation with μm thickness. The X-ray detector based on inorganic perovskite shows good environmental stability and high X-ray sensitivity. Owing to anisotropic carrier transport capability, two-dimensional layered perovskites with a preferred orientation parallel to the substrate can effectively suppress the dark current of the device despite poor light response to X-rays, resulting in lower sensitivity for the device. Double perovskite applied for X-ray detectors shows better attenuation of X-rays due to the introduction of high-atomic-numbered elements. Additionally, its stable crystal structure can effectively lower the dark current of X-ray detectors. Environmentally friendly lead-free perovskite exhibits potential application in X-ray detectors by virtue of its high attenuation of X-rays. In the last section, we specifically introduce the up-scaling process technology for fabricating large-area and thick perovskite films for X-ray detectors, which is critical for the commercialization and mass production of perovskite-based X-ray detectors.

Keywords: X-ray detector; double perovskite; inorganic perovskite; lead-free perovskite; perovskite; photoelectronic effect; two-dimensional layered perovskite.

Figure 1

Application of organic–inorganic hybrid perovskite SCs in X-ray detectors. (a) Schematic diagram of the working principle for the X-ray detector with different surface treatments [31]. (b) Schematic diagram of the crystallization process for the MAPbI₃ SCs with small and large temperature gradients [35]. (c) Schematic diagram of a device with Au/MAPbBr₃ SCs/Al architecture [38]. (d) Different perovskite SCs fabricated by thermal evaporation and X-ray images of a closed black plastic box measured by the FAMACs-SC-based X-ray detector [41].

Figure 2

(a) Device structure, (b) dark current density and (c) photocurrent of self-powered X-ray detector based on 2D (F-PEA)₂PbI₄ perovskite [53]. (d) Schematic diagram of Cu ion implantation on the (PMA)₂PbI₄-based X-ray detector. (e) Sensitivity and (f) detection limit of (PMA)₂PbI₄-based X-ray detector after ion implantation [54]. (g) Schematic diagram of tableting process for the (F-PEA)₃BiI₆ SCs. Photocurrent of X-ray detector using (F-PEA)₃BiI₆ single crystal under (h) vertical and (i) horizontal electric fields [55].

Figure 3

(a) Photoconductor-type X-ray detectors by deposition of 2D PEA₂PbBr₄ micro-crystalline films on a flexible PET substrate. (b) Sensitivity per unit area (S_A, black curve) and photocurrent (orange curve) as a function of dose rate. (c) SNR as a function of dose rate for the device under 150 kVp (blue curve) and 40 kVp (orange curve) accelerating voltages [51].

Figure 4

(a) Crystal structure of the quasi-2D BA₂EA₂Pb₃Br₁₀ perovskite. (b) X-ray-generated photocurrent of BA₂EA₂Pb₃Br₁₀ perovskite at various dose rates at a bias of 10 V [56]. (c) A p–i–n device architecture and (d) J–V curve of X-ray detector based on quasi-2D (BA)₂(MA)₂Pb₃I₁₀ perovskite [57]. (e) Fabrication process of thick film growth of quasi-2D perovskite and (f) J–V curve of corresponding X-ray detector [58].

Figure 5

(a) Schematic illustration of electrostatic-assisted spray coating process for deposition of large-area Cs₂TeI₆ perovskite. (b) Comparison of attenuation efficiency of CdTe, a-Se and Cs₂TeI₆ with different thicknesses for X-ray irradiation. Inset illustrates the device structure [60]. (c) J–V curves and (d) photocurrent as a function of dose rate of X-ray detector using Cs₄PbI₆ single crystal [61].

Figure 6

(a) Photo of X-ray detector with a device architecture of Au/Cs₂AgBiBr₆ perovskite/Au [62]. (b) I–V curves of X-ray detectors using pristine Cs₂AgBiBr₆ and PEA-Cs₂AgBiBr₆ single-crystal. (c) X-ray response of the Cs₂AgBiBr₆- and PEA-Cs₂AgBiBr₆-based devices [64].

Figure 7

(a) FA₃Bi₂I₉ single crystal synthesized by the solution method through controlling the growth mechanism [67]. (b) Schematic diagram of preparation of the Cs₃Bi₂I₉ single crystals by the nucleation-controlled solution method [68].

Figure 8

Application of large-area perovskite film for X-ray detectors. (a) Reliability of sensitivity for X-ray detectors fabricated on rigid and flexible substrates [69]. (b) Photo of large-area CsPbBr₃ quantum dots deposited on TFT array [70]. (c) Illustration of working principle of X-ray detector using mixed Cs₂AgBiBr₆/(C₃₆H₃₄P₂)MnBr₄ scintillator [71]. (d) Cross-sectional SEM and X-ray photo-response of the device with bar coating of MAPbI₃:PC60BM mixed absorber [72]. (e) Large-area lead-free Cs₂TeI₆ perovskite fabricated by electro-spraying on flexible substrates and the relationship between the photocurrent density of Cs₂TeI₆-based device and the exposure dose rate [73]. (f) Schematic illustration of the perovskite layer prepared by the ALS process [74].