Observation of ultraviolet photothermoelectric bipolar impulse in gallium-based heterostructure nanowires

• Published in: Nature communications Vol. 16; no. 1; pp. 1186 - 10
• Main Authors: Zhu, Jinjie, Cai, Qing, Shao, Pengfei, Zhang, Shengjie, You, Haifan, Guo, Hui, Wang, Jin, Xue, Junjun, Liu, Bin, Lu, Hai, Zheng, Youdou, Zhang, Rong, Chen, Dunjun
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 30.01.2025; Nature Publishing Group; Nature Portfolio
• Subjects: 147/135; 147/143; 639/624; 639/925; Carrier transport; Cell interactions; Concentration gradient; Current carriers; Electrochemical cells; Electrochemistry; Energy conversion; Gallium; Gallium nitrides; Group III-V semiconductors; Harnesses; Heterojunctions; Heterostructures; Humanities and Social Sciences; Impulse response; multidisciplinary; Nanotechnology; Nanowires; Optoelectronics; Photothermal conversion; Science; Science (multidisciplinary); Ultraviolet detectors
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-025-56617-z

The incorporation of thermal dynamics alongside conventional optoelectronic principles holds immense promise for advancing technology. Here, we introduce a GaON/GaN heterostructure-nanowire ultraviolet electrochemical cell of observing a photothermoelectric bipolar impulse characteristic. By leveraging the distinct thermoelectric properties of GaON/GaN, rapid generation of hot carriers establishes bidirectional instantaneous gradients in concentration and temperature within the nanoscale heterostructure via light on/off modulation. The thermoelectromotive force induced by these gradients, combined with the type-II heterojunction band structure, facilitates carrier transport, resulting in transient bidirectional photothermal currents. The device achieves exceptional responsivity (17.1 mA/W) and remarkably fast speed (8.8 ms) at 0 V, surpassing existing semiconductor electrochemical cells. This bipolar ultraviolet impulse detection mode harnesses light-induced heat for electricity generation, enabling innovative bidirectional encryption communication capabilities. Anticipated applications encompass future sensing, switchable light imaging, and energy conversion systems, thereby laying a foundation for diverse optoelectronic technological advancements. III-V group semiconductor has garnered attention in photothermoelectric field. Here, the authors present a GaON/GaN nanowire-based ultraviolet photothermoelectric detector and describe the physical process of the observed bipolar impulse response.