Piezophototronic Effect-Enhanced Highly Sensitive Flexible Photodetectors Based on Electrohydrodynamic Direct-writing Nanofiber Self-stacking

Flexible photodetectors are ideal for short-range communication in lightweight microintegrated systems. However, low-bonding interface and high-power cost of photosensitive components greatly limit their application in flexible communication systems. To address this, herein, piezophototronic effect-enhanced sensing components are proposed for flexible photodetectors. This approach leverages the piezophototronic effect to modulate nanoscale charge transport and the precision of electrohydrodynamic direct-writing to achieve controlled nanofiber assembly, thereby enhancing interfacial bonding and overall device performance. By employing electrohydrodynamic direct-writing, a copper-ammonia complex ((Cu(NH₃))(CN)) nanofiber is self-stacked on a zinc oxide (ZnO) nanofiber to construct a zinc oxide and copper ammine complex (ZnO@(Cu(NH₃))(CN)) photodetector with low static power consumption and high responsiveness through the combined effects of piezoelectricity and fiber self-stacking. The dark current is reduced to 1.12 × 10⁻⁷ A, and the static power consumption of the photodetector is also decreased. The responsiveness is up to 13.3 A/W, with response and recovery times of 11 and 9 ms under ultraviolet (UV) light illumination, respectively, fulfilling the requirements for highly sensitive photodetection owing to the high interface bonding. The detector's threshold voltage is tunable, ranging from 6 V for 5 stacking layers to 20 V for 25 stacking layers, thereby allowing the device's performance to be precisely tailored to specific application requirements. Leveraging the exceptional optoelectronic performance of the ZnO@(Cu(NH₃))(CN) photodetector, this study expands the application scenarios of flexible photodetectors and demonstrates their potential in the fields of 6G technology and battlefield communication.

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