Template growth of perovskites on yarn fibers induced by capillarity for flexible photoelectric applications

With intense interest in lead halide perovskites for flexible optoelectronic applications, shape-controlled preparation of fibrous perovskites with high stress tolerance is desirable. We report a template synthesis method for obtaining fibrous perovskite materials, by using the capillary effect of a precursor solution. Fibrous yarn bundles, which are highly flexible and can be knitted into various patterns, are used as a template to form MAPbI3 with controllable dimensionality and morphology. On the basis of this, we further design and successfully obtain a “quasi-spring” like network based flexible photodetector. The device exhibits impressive photoelectric characteristics, that is, an ON/OFF ratio of ∼4.5 × 104, a fast photo-response speed (trise ∼ 4 ms and tdecay ∼ 10 ms at an illumination density of 80 mW cm−2), and a detectivity of 2.2 × 1011 Jones (at an illumination density of 10 μW cm−2). Furthermore, the device exhibits a minute photocurrent attenuation after 200 bending cycles, and is able to work stably even in a twisted state at 180°. This work provides a method for the controllable growth of perovskite materials, which will yield promising opportunities for constructing integrated crooked and different dimensional perovskites and optoelectronic systems.