Boosting Fiber-Shaped Photodetectors via "Soft" Interfaces.

Lightweight, flexible fiber-shaped devices that can be woven into wearable electronic products have received great attention in recent years. However, the bending and poor interfaces of fiber-shaped devices typically lead to ineluctable performance degradation, which is still a great challenge yet to be dealt with. Here, taking a fiber-shaped photodetector as an example, we proposed an effective strategy, constructing inorganic-organic-graphene hybrid interfaces on a single fiber, to greatly improve the performances of fiber-shaped device. In the proposed structure, the ZnO nanorod array is grown vertically on the surface of a Zn wire (center core) and then wrapped by PVK and graphene (outmost layer) as the two outer layers. These "soft" interfaces successfully built compact contacts between various functional layers even on curved interfaces, which markedly reduced the contact resistance. Meanwhile, the whole structure also exhibited excellent durability toward the bending operations. Evidently, the Ilight/Idark ratio and photoresponsivity under bias of 0.5 V are as high as 7.2 and 0.9 A/W. In particular, the photoresponse speed has been greatly improved with the rise time of 280 ms, which was 1 order of magnitude faster than that of other fiber-shaped photodetectors without the above "soft" interfaces.