High-Performance Flexible Broadband Photoelectrochemical Photodetector Based on Molybdenum Telluride

Flexible broadband photodetectors are desired but challenging to be fabricated for next-generation wearable intelligent optoelectronic devices. Considering the narrow bandgap and strong light absorption, molybdenum telluride (MoTe2 ) based photoelectrochemical photodetectors are successfully assembled by liquid phase exfoliation accompanied with the electrophoretic deposited method. This MoTe2 -based photodetector shows a broadband detection in ultraviolet-near-infrared band, long-term stability within 18000 s, and fast response in millisecond-level (response time≈19 ms, recovery time≈26 ms). More importantly, even though the MoTe2 photodetector is bent and twisted at a high degree for several hundred times, it still shows excellent flexibility with stable on-off switching characteristics. Additionally, this photodetector displays a good response for rotation angles in the range from 0° to 360°, and the extracted Iph maintain almost the same value approximately 0.97 µA cm-2 , suggesting an omnidirectional detection capability. This work demonstrates the proposed flexible photoanode shows a great potential in future broadband omnidirectional detection systems.

Flexible Double-Sided Light-Emitting Devices Based on Transparent Embedded Interdigital Electrodes

In the areas of flexible displays and wearable devices, double-sided light-emitting devices have huge commercial applications. Here, we provide a novel form of flexible double-sided light-emitting devices by designing and manufacturing different transparent interdigital electrodes for lighting the structural areas of composite emitting layers. The transparent interdigital electrodes are fabricated by embedding multiwalled carbon nanotubes in interdigital mesh-structured microcavities using a doctor-blading process, and the emitting layers are fabricated by mixing copper-doped zinc sulfide (ZnS/Cu) phosphor particles with the transparent polydimethylsiloxane polymer. The fabricated double-sided light-emitting devices could be in the crimp state, exhibiting excellent flexibility. By designing the structure of the interdigital electrodes and the thickness of the emitting layers, the double-sided emission intensity of the light-emitting devices can be adjusted. Furthermore, based on the flexible double-sided light-emitting devices, various patterns can be successfully programed, such as the digital, grayscale, and ancient Chinese walls. The flexible and programmable double-sided light-emitting films provide a promising strategy for the next generation of customized flexible displays.

Coating Solution for High-Voltage Cathode: AlF3 Atomic Layer Deposition for Freestanding LiCoO2 Electrodes with High Energy Density and Excellent Flexibility

Freestanding LiCoO₂/multiwall carbon nanotube/nanocellulose fibril (LCO-MWCNT-NCF) electrodes are fabricated by a vacuum filtration technique. The electrode has a high LCO loading of 20 mg/cm² with excellent flexibility, uniform material distribution, and low surface resistivity. When coated with 2 ALD cycles of AlF₃, LCO-MWCNT-NCF has a high specific capacity of 216 mAh/g at 4.7 V. The freestanding AlF₃-coated electrode preserves 75.7% of its initial capacity after 100 cycles and 70% after 160 cycles of charge discharge. In contrast, electrodes coated with 2 ALD cycles of Al₂O₃ cannot be cycled above 4.5 V. By elimination of the unnecessary weight of current collector, and increasing in the working voltage simultaneously, this freestanding LCO-MWCNT-NCF electrode can significantly improve the gravimetric and volumetric energy density of lithium ion batteries.