Stretchable Photodetectors Based on Electrospun Polymer/Perovskite Composite Nanofibers

Polymer/lead halide perovskite composites are a promising platform for wearable optoelectronic devices. In particular, one-dimensional nanocomposites are considered core materials for solar energy conversion textiles and optical sensors. Herein, we designed stretchable photodetectors incorporating thin and uniform polymer/perovskite composite nanofibers produced by electrospinning of a polymer/perovskite precursor solution. During the reaction of precursors in the as-spun nanofiber, protruding perovskite nanoplates on the fiber surface and embedded nanoparticles within the fiber were formed, showing double photoluminescence emissions. Furthermore, the mechanical behavior of the nanofibers on a rubbery substrate strongly depends on their orientation angle (α) with respect to the applied tensile force. As α decreases, the loaded stress is significantly reduced, which contributes to a stretchability of up to 15% strain for any orientation. The excellent percolation of perovskite nanoparticles leads to high photocurrents under green and red light illumination. At 15% strain, the responsivity and detectivity of the stretchable photodetector at λ = 550 nm were 51.2 mA W^–1 and 2.23 × 10¹¹ Jones, respectively. The device performance was well retained during mechanical deformation and stability tests. This thin and stretchable device was also applied to a wearable photodetector to demonstrate its great potential as a wearable image sensor.