Fully printed flexible solar-blind self-powered photodetector based on atomic-thin wide bandgap heterostructure

The demand for cost-effective and scalable manufacturing processes in flexible functional device fabrication has led to the exploration of novel materials and innovative fabrication techniques for wearable health monitoring systems. However, ultraviolet (UV) photodetectors, due to wide band gap responsive substance with complicated synthesis, always require an external power supply and suffer low response rates and slow response times. Here, we present a solution-processed scalable ink-printed integrated ultraviolet (UV) photodetector based on granular-derived power-intercalated Bi₂O₂Se/Bi₂SeO₅ heterostructure nanosheets, a promising two-dimensional (2D) semiconductor with notable optical and electrical properties. By employing fine and highly conductive MXene-Pt-Ni current collectors, Bi₂O₂Se/Bi₂SeO₅ heterostructure UV photodetector demonstrates impressive performance in the UV spectral range, showcasing high responsivity and rapid photoresponse, with diverse applications from wearable electronics to environmental monitoring systems. The device exhibits a notable photocurrent on/off ratio and low dark current, with photocurrent density (<em>I</em>_ph) of 2.2 μA cm⁻² and photodetectivity D* of 3.31×10¹⁰ Jones, outperforming previously reported all-printed devices, highlighting its potential for low-power and high-performance applications. Moreover, integrating the photodetector into a printed electronics platform enables seamless incorporation into flexible and conformal systems, extending its utility in various form factors and applications.