The p-n junction with bipolar characteristics sets the fundamental unit to build electronics while its unique rectification behavior constrains the degree of carrier tunability for expanded functionalities. Herein, we report a bipolar-junction photoelectrode employed with gallium nitride (GaN) p-n homojunction nanowire array that operates in electrolyte, demonstrating bipolar photoresponse controlled by different wavelengths of light. Significantly, with rational decoration of a ruthenium-oxides (RuOx) layer on nanowires guided by theoretical modeling, the resulted RuOx/p-n GaN photoelectrode exhibits unambiguously boosted bipolar photoresponse by an enhancement of 775% and 3000% for positive and negative photocurrents, respectively, compared to the pristine nanowires. The loading of RuOx layer on nanowire surface optimizes surface band bending which facilitates charge transfer across the GaN/electrolyte interface, meanwhile promoting the efficiency of redox reaction for both hydrogen evolution reaction and oxygen evolution reaction which corresponds to the negative and positive photocurrents, respectively. Finally, a dual-band optical communication system incorporated with such photoelectrode is constructed with using only one photoelectrode to decode dual-channel signals with encrypted property. The proposed bipolar device architecture presents a viable route to manipulate the carrier dynamics for the development of a plethora of multi-functional optoelectronic devices for future sensing, communication, and imaging systems.
|Original language||English (US)|
|State||Published - Mar 13 2023|
Bibliographical noteKAUST Repository Item: Exported on 2023-03-16
Acknowledgements: This work was funded by the National Natural Science Foundation of China (Grant No. 52272168, 52161145404), the Fundamental Research Funds for the Central Universities (Grant No. WK3500000009), International Projects of the Chinese Academy of Science (CAS)under Grant No. 211134KYSB20210011 and was partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication. Thanks to Prof. Zhenghui Liu and Boyang Liu for the support of KPFM measurements.
ASJC Scopus subject areas
- Mechanics of Materials
- Materials Science(all)
- Mechanical Engineering