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Strain-Tolerant, High-Detectivity and Intrinsically Stretchable All-Polymer Photodiodes

Journal
Advanced Functional Materials
Date
2023.01.18
Abstract

A skin-like photodiode (PD) that is stretchable and skin-conformable is crucial to opening the next-generation wearable electronics for optical biometric monitoring, biomedical imaging and others. To achieve reliable PD characteristics under large deformation, stretchable PDs with high detectivity and high mechanical stretchability must be developed. Here, we demonstrate intrinsically stretchable polymer-based PDs (is-PPDs) comprising all-polymeric constituent layers. In particular, elastomeric photoactive layers consisting of an elastomer with p-/n-type semiconducting polymers and conducting polymer-based stretchable transparent electrodes with modulated work functions improved both the mechanical stability and the detectivity (D*) of is-PPDs. Accordingly, is-PPDs showed excellent D* over 1013 Jones with a suppressed dark current density of 0.1 nA/cm2 before and after 100% stretching. The proposed is-PPDs recorded high-quality and stable photoplethysmography signals at the wrist with outward extension.

Reference
Adv. Funct. Mater. 2023 (adfm.202212219)
DOI
http://dx.doi.org/10.1002/adfm.202212219