Strides in zinc oxide nanostructures push state of the art in self-powered photodetectors

Self-powered photodetectors have long been sought after for next-generation optoelectronic devices because of their low reliance on external power sources. One favorited material for self-powered photodetectors is zinc oxide.

Ouyang et al. highlight the various ZnO nanostructures used in self-powered UV photodetectors and how various material properties and specific effects impact the self-powered photoresponse. Analysis of as-obtained electrical signals from the photodetectors provides a path forward for acquiring relevant information about incident light. The authors then outline the applications and developing trends for the future use of these devices.

“Imagine that you can wear a transparent integrated device on your wrist, which could provide environmental information, such as the real-time UV intensity, temperature, and concentration of toxic gases around you, you might also receive customized information via safe light communication” said author Xiaosheng Fang.

There is one key weakness in these self-powered photodetections, even with the ZnO nanomaterials. The current output signals are still not large enough to be measured and displayed by conventional and small-sized instruments.Obtaining measurements precise enough requires bulky, expensive and delicate instruments, which restricts the practical application of these photodetectors.

“One possible solution to cope with this challenge is to pursuit the high sensitivities of these photodetectors, so as to produce larger output signals and meet with the ‘5S’ standard that defines the requirements for high sensitivity, signal-to-noise ratio, spectral selectivity, speed and stability of practical photoelectric devices.” Fang said.

Fang sees the field eventually supporting bionic photoelectric devices by approaching the high-efficiency energy conversion of biomolecules such as chlorophyll.

Source: “Self-powered UV photodetectors based on ZnO nanomaterials,” by Weixin Ouyang, Jiaxin Chen, Zhifeng Shi, and Xiaosheng Fang, Applied Physics Reviews (2021). The article can be accessed at https://doi.org/10.1063/5.0058482 .