Optical resonance formed inside a nanocavity resonator can trap light within the active region and hence enhance light absorption, effectively boosting device or material performance in applications of solar cells, photodetectors (PDs), and photocatalysts. Complementing conventional circular and spherical structures, a new type of multishelled spherical resonant strategy is presented. Due to the resonance-enhanced absorption by multiple convex shells, ZnO nanoshell PDs show improved optoelectronic performance and omnidirectional detection of light at different incidence angles and polarization. In addition, the response and recovery speeds of these devices are improved (0.8 and 0.7 ms, respectively) up to three orders of magnitude faster than in previous reports because of the existence of junction barriers between the nanoshells. The general design principles behind these hollow ZnO nanoshells pave a new way to improve the performance of sophisticated nanophotonic devices.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The authors thank Yu-Hsuan Hsiao and Hui-Chun Fu for technical support and helpful discussions. The authors thank the support by the King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR-2016-CRG5-3005), KAUST Sensor Initiative, KAUST Solar Center, and KAUST baseline funding and the Chinese Academy of Sciences and the National Natural Science Foundation of China (No. 21031005).