Enhanced Photoresponse Performance of Self-Powered PTAA/GaN Microwire Heterojunction Ultraviolet Photodetector Based on Piezo-Phototronic Effect

The development of self-powered high-performance UV photodetectors is essential for energy efficient futuristic wearable and portable applications. Herein, a self-powered organic/inorganic (PTAA/GaN microwire) hybrid heterojunction ultraviolet (UV) photodetector (PD) has been prepared by a low-cost and simple spin-coating method. Furthermore, the piezo-phototronic effect as an effective interfacial regulating strategy is utilized to modulate the photoresponse performances of the PD by engineering the energy-band structure at the local junction/interface. Under 325 nm laser irradiation, the obtained device demonstrates excellent photo-response properties at 0 V bias, showing a high responsivity (268 mA W-1) and detectivity (2.49 x 10(12) Jones) under weak light intensity as low as 0.2 mW cm(-2), as well as fast response speeds (rise time of 14 ms and decay time of 23 ms). The PD exhibits better performance than most reported organic/inorganic heterojunction self-powered PDs. By applying a -0.52% compressive strain, the responsivity and detectivity of the device are greatly enhanced by 32% without external bias, and by 1256% at 2 V bias under 1.4 mW cm(-2) light intensity. On the contrary, by applying a 0.41% tensile strain, the responsivity and detectivity are decreased by 18% without external bias. It indicates that the strain has a significant modulating effect on the photo-response performance of the PD. The positive piezo-potential modulated energy-band structure at the PTAA/GaN interface may account for the enhanced performance. This study demonstrates a promising approach to optimize the performance of a self-powered heterostructure optoelectronic devices through strain modulated.

Automated summary

The development of self-powered high-performance UV photodetectors is crucial for energy-efficient wearable and portable applications. In this study, a self-powered organic/inorganic hybrid UV photodetector was prepared using a low-cost and simple spin-coating method. The photoresponse performances of the photodetector were modulated by the piezo-phototronic effect, resulting in excellent properties such as high responsivity, detectivity, and fast response speeds. This research demonstrates a promising approach to optimize the performance of self-powered heterostructure optoelectronic devices through strain modulation.