Sensitive Direct Converting X‐Ray Detectors Utilizing Crystalline CsPbBr₃ Perovskite Films Fabricated via Scalable Melt Processing

Abstract

Here the fabrication of an inorganic metal‐halide perovskite CsPbBr3 based X‐ray detector is reported utilizing a simple, scalable, and cost‐sensitive melt processing directly on substrate of any size. X‐ray diffraction analysis on the several 100 mm thick melt processed films confirms crystalline domains in the cm2 range. The CsPbBr3 film features a resistance of 8.5 GΩ cm and a hole mobility of 18 cm2 V−1 s−1. An X‐ray to current conversion rate of 1450 mC Gyair−1 cm−2 at an electric field of 1.2 × 104 V cm−1 and a detection limit in the sub µGyair s−1 regime is demonstrated. The high crystallinity and chemical purity of the melt processed CsPbBr3 films are suggested to be responsible for a performance which is on par to current state‐of‐the‐art Cd(Zn)Te based X‐ray detector technology.

Designing Ultraflexible Perovskite X‐Ray Detectors through Interface Engineering

“…[55] Therefore, the combination of high X-ray induced photocurrent and low dark current in PEDOT/Per/PCBM/TiO x yields a low limit of detection of about 0.58 ± 0.05 Gy s −1 (defined as three times the detector noise) ( Figure S5, Supporting Information). This value is the lowest among perovskite thin film detectors [39,46,58] and it compares well with other thick perovskite X-ray detectors, [18,34] while also being considerably below the medical requirements for diagnostics (≈5 Gy s −1 ). [59,60] We also compare the influence of HTL by examining the performance of PEDOT/Per/PCBM/BCP (Figure 2a) and NiO x /Per/PCBM/BCP (LC) (Figure 2c) detector architectures.…”

“…b) Photograph of the ultraflexible X-ray detector held with tweezers after detaching (scale bar 5 mm). c) Comparison of the dynamic response between the detector on the glass support (continuous lines) and the same device in the free-standing configuration (dotted lines) at different dose rates (18,35, and 52 mGy s −1 ). Free-standing devices show slower response time, but improved detection performance.…”

“…the patient must be kept as low as possible. Figure 4c shows the comparison of dynamic response between the detector on glass support and in free-standing form to three cycles of X-ray irradiation at three different dose rates (18,35, and 52 mGy s −1 ). Interestingly, the free-standing X-ray photodiode photocurrent amplitude does not degrade, but rather slightly increases ( Figure S9, Supporting Information).…”

“…Recently, lead-halide perovskites emerged as an auspicious novel materials family for X-and gamma-ray detection. [17][18][19] Their success can be attributed to strong absorption of ionizing radiation due to presence of heavy atoms (Pb, I, and Br), high charge carrier mobilities, long exciton diffusion, long charge carrier lifetime, and excellent optical properties. [20][21][22][23][24] Single crystal [19,[25][26][27][28][29][30][31] and thick film [32][33][34][35][36] perovskite X-ray detectors have been the focal point of current research, often incorporated in a lateral photoconductor radiation detector architecture.…”

All-organic composites with strong photoelectric response over a wide spectral range

“…Conventional photodetector materials are usually designed based on the two common operational mechanisms of semiconductor materials. Photoconductive materials can detect light through the change in the conductivity of the material due to exposure to light [17,18] and show good photosensitivity in a relatively wide spectral range [19][20][21][22][23]. Unlike photoconductors, photodiodes with heterojunction structures generate a photoelectric response directly under light irradiation based on the photovoltaic effect and do not require an external power source [24,25].…”