Solid-state radiation detectors, using crystalline semiconductors to convert radiation photons to electrical charges, outperform other technologies with high detectivity and sensitivity. Here, we demonstrate a thin-film x-ray detector comprised with highly crystalline two-dimensional Ruddlesden-Popper phase layered perovskites fabricated in a fully depleted p-i-n architecture. It shows high diode resistivity of 1012 ohm·cm in reverse-bias regime leading to a high x-ray detecting sensitivity up to 0.276 C Gyair−1 cm−3. Such high signal is collected by the built-in potential underpinning operation of primary photocurrent device with robust operation. The detectors generate substantial x-ray photon–induced open-circuit voltages that offer an alternative detecting mechanism. Our findings suggest a new generation of x-ray detectors based on low-cost layered perovskite thin films for future x-ray imaging technologies.

Hybrid perovskites have emerged as the most promising thin-film photovoltaic technology with efficiencies exceeding 20% merely in the last five years. Most highefficiency perovskite solar cells reported in the recent years have relatively small device area in comparison to that required for commercial photovoltaic modules. While these results are excellent from an academic perspective, scaling up the overall cell device area is crucial for achieving practical utility for hybrid perovskite based thin-film solar cells. In this paper, we present a comprehensive study on the use of temperature-controlled doctor blading technique for the growth of large island, crystalline perovskite thin-films. Specifically, we elucidate the physical conditions such as substrate temperature, solution volume, and blade speed under ambient conditions that control the growth of large area perovskite thin-films with desired island size, thickness, uniformity and crystallinity. Using these doctor-bladed thin-films we fabricated devices of ~1 cm 2 area in air that yielded an average efficiency of 7.32% with negligible hysteresis in the current-voltage scans. Further improvements in efficiency can be expected by reproducing the perovskite thin-film growth using doctor-blading in a controlled environment, through compositional tuning of the band-gap, or by selecting electron and hole transport layers with better band alignment with the perovskite electronic energy level.

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Despite the remarkable optoelectronic properties of halide perovskites, achieving reproducible field effect transistor (FET) action in polycrystalline films at room temperature has been challenging and represents a fundamental bottleneck for understanding electronic charge transport in these materials. In this work, we report halide perovskite-based FET operation at room temperature with negligible hysteresis. Extensive measurements and device modeling reveal that incorporating high-k dielectrics enables modulation of the channel conductance. Furthermore, continuous bias cycling or resting allows dynamical reconfiguration of the FETs between p-type behavior and ambipolar FET with balanced electron and hole transport and an ON/OFF ratio up to 10 4 and negligible degradation in transport characteristics over 100 cycles. These results elucidate the path for achieving gate modulation in perovskite thin films and provide a platform to understand the interplay between the perovskite structure and external stimuli such as photons, fields, and functional substrates, which will lead to novel and emergent properties.