Vacuum-Deposited Perovskite Photodiodes for Visible and X-Ray Photon Detection

Metal halide perovskite photodiodes have garnered extensive attention owing to their favorable optoelectronic properties, rendering them attractive for visible, near-infrared, and X-ray sensors. However, their predominant reliance on solution-processing deposition techniques poses challenges for seamless integration into existing industrial processes. In this study, this limitation is addressed by developing fully vacuum-processed perovskite photodiodes with varying hole transport layers (HTL). These findings underscore the critical role of HTL selection in influencing the dark and noise current characteristics of the diodes. With an optimized HTL, photodiodes are obtained with low noise current (approximate to 3 10-14 A Hz-1/2) and high specific detectivity (approximate to 1012 Jones at 710 nm at -0.5 V). The photodiodes are also tested as X-ray detectors and are found to be stable under X-ray radiation, with state-of-the-art sensitivity of 33 +/- 4 mu C Gy-1 cm-2 and a low limit of detection of 2.0 +/- 1.6 mu G s-1. These insights contribute to the development of perovskite photodiodes with improved performance and broader industrial applicability.Fully vacuum-processed perovskite photodiodes with varying hole transport layers (HTL) are investigated. These findings underscore the critical role of HTL selection in influencing the dark and noise current characteristics of the diodes. With an optimized HTL, photodiodes are obtained with low noise current, high specific detectivity, and state-of-the-art X-ray sensitivity. imag

Roadmap on printable electronic materials for next-generation sensors

The dissemination of sensors is key to realizing a sustainable, ‘intelligent’ world, where everyday objects and environments are equipped with sensing capabilities to advance the sustainability and quality of our lives—e.g., via smart homes, smart cities, smart healthcare, smart logistics, Industry 4.0, and precision agriculture. The realization of the full potential of these applications critically depends on the availability of easy-to-make, low-cost sensor technologies. Sensors based on printable electronic materials offer the ideal platform: they can be fabricated through simple methods (e.g., printing and coating) and are compatible with high-throughput roll-to-roll processing. Moreover, printable electronic materials often allow the fabrication of sensors on flexible/stretchable/biodegradable substrates, thereby enabling the deployment of sensors in unconventional settings. Fulfilling the promise of printable electronic materials for sensing will require materials and device innovations to enhance their ability to transduce external stimuli—light, ionizing radiation, pressure, strain, force, temperature, gas, vapours, humidity, and other chemical and biological analytes. This Roadmap brings together the viewpoints of experts in various printable sensing materials—and devices thereof—to provide insights into the status and outlook of the field. Alongside recent materials and device innovations, the roadmap discusses the key outstanding challenges pertaining to each printable sensing technology. Finally, the Roadmap points to promising directions to overcome these challenges and thus enable ubiquitous sensing for a sustainable, ‘intelligent’ world

Low-cost monolithic processing of large-area ultrasound transducer arrays

Large-area flexible ultrasound arrays can offer new ultrasound modalities in multiple fields. The production of these arrays when using CMOS-type fabrication techniques faces scalability challenges and costs increase dramatically when upscaled to large dimensions. We investigate the monolithic production of large-area PPT (Printed Polymer Transducer) arrays directly on a flexible substrate. Here, a vibrating membrane is defined by a circular opening in a thick photoresist layer. Since the photoresist layer is processed on top of the P(VDF-TrFE), a thin barrier layer is used to prevent diffusion into the P(VDF-TrFE). An annealing procedure is developed to reduce the surface roughness of the P(VDF-TrFE) layer and make it compatible with thin film electrode deposition. We measure a remnant polarization of 7-8 μC/cm2 and a coercive field of around 50 MV/m. Laser scanning vibrometer measurements reveal a uniform peak displacement and fundamental resonance frequency (66 kHz) across the PPT array

Vacuum-Deposited Perovskite Photodiodes for Visible and X-Ray Photon Detection

Metal halide perovskite photodiodes have garnered extensive attention owing to their favorable optoelectronic properties, rendering them attractive for visible, near-infrared, and X-ray sensors. However, their predominant reliance on solution-processing deposition techniques poses challenges for seamless integration into existing industrial processes. In this study, this limitation is addressed by developing fully vacuum-processed perovskite photodiodes with varying hole transport layers (HTL). These findings underscore the critical role of HTL selection in influencing the dark and noise current characteristics of the diodes. With an optimized HTL, photodiodes are obtained with low noise current (≈3 10−14 A Hz−1/2) and high specific detectivity (≈1012 Jones at 710 nm at −0.5 V). The photodiodes are also tested as X-ray detectors and are found to be stable under X-ray radiation, with state-of-the-art sensitivity of 33 ± 4 µC Gy−1 cm−2 and a low limit of detection of 2.0 ± 1.6 µG s−1. These insights contribute to the development of perovskite photodiodes with improved performance and broader industrial applicability

Low-cost monolithic processing of large-area ultrasound transducer arrays

\u3cp\u3eLarge-area flexible ultrasound arrays can offer new ultrasound modalities in multiple fields. The production of these arrays when using CMOS-type fabrication techniques faces scalability challenges and costs increase dramatically when upscaled to large dimensions. We investigate the monolithic production of large-area PPT (Printed Polymer Transducer) arrays directly on a flexible substrate. Here, a vibrating membrane is defined by a circular opening in a thick photoresist layer. Since the photoresist layer is processed on top of the P(VDF-TrFE), a thin barrier layer is used to prevent diffusion into the P(VDF-TrFE). An annealing procedure is developed to reduce the surface roughness of the P(VDF-TrFE) layer and make it compatible with thin film electrode deposition. We measure a remnant polarization of 7-8 μC/cm\u3csup\u3e2\u3c/sup\u3e and a coercive field of around 50 MV/m. Laser scanning vibrometer measurements reveal a uniform peak displacement and fundamental resonance frequency (66 kHz) across the PPT array.\u3c/p\u3