Molecular Suturing Enabled Strong and Ultrahigh-Responsivity Janus 2D Semiconductor Fibers for Self-Powered Wearable...

Constructing semiconductor heterostructure fiber (SHF) is a crucial strategy to advance next-generation textile-based wearable, self-powered, and long-termly comfortable optoelectronic platforms. However, in current SHF, carrier extraction/transport and stress transfer across the heterointerface usually encounter huge hindrances due to the uncontrolled structural defects (e.g., vacancies, voids, and misalignment). In this work, a molecular suturing strategy is proposed to construct meter-scale Janus WSe₂/MoS₂ SHF with highly aligned, densified, and electronically interconnected heterointerface by utilizing a conjugated molecular (i.e., 1,5-Naphthalenedithiol, NTD) as carrier viaduct and mechanical solder to engineer the structural defects. The obtained NTD-WSe₂/MoS₂ SHF exhibits over 16-fold higher responsivity (210.3 mA/W at zero bias) than previous self-powered fiber photodetectors, over 2 orders of magnitude faster photoresponse speed (38 ms) than pristine counterpart, reliable bending robustness (90.2% photocurrent retention after 60 000 bending cycles), and over threefold higher tensile strength/modulus than previous semiconductor fibers. Benefiting from these desirable performances, a robust and wearable self-powered textile photoplethysmography sensing platform is successfully developed to realize long-term (exceed 30 days) biosignal tracking. This work provides a scalable strategy for further developments of advanced wearable fiber optoelectronics.