Bendable ITO-free Organic Solar Cells with Highly Conductive and Flexible PEDOT:PSS Electrodes on Plastic Substrates

Flexible and transparent electrodes have great potential for photon transmission and charge-carrier collection for next generation electronics compared to rigid electronics with indium tin oxide (ITO)-coated glass substrates. This study describes a comprehensive study of the electrical, morphological, optical, structural, and mechanical properties of poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS) films treated by methanol and methanesulfonic acid (MSA), which are coated on hydrophobic flexible plastic substrates. Such a film coated on hydrophobic plastic substrates exhibits a high conductivity up to 3560 S cm^–1 and a good mechanical flexibility. Moreover, the use of the films to fabricate bendable ITO-free organic solar cells (OSCs) integrated on plastic substrates was presented. The bendable devices based on P3HT:PCBM not only exhibit a high power conversion efficiency (PCE) up to 3.92%, which is comparable to 4.30% of the rigid devices with ITO-coated glass substrates, but also keep about 80% in PCE of the initial value after 100 time bending with a bending radius of 14 mm in the ambient atmosphere. This work provides a novel route to dramatically improve the conductivity of PEDOT:PSS electrodes, as well as the mechanical flexibility of highly efficient organic electronics with the flexible electrodes

Nature-Inspired Surface Engineering for Efficient Atmospheric Water Harvesting

Atmospheric water harvesting is a sustainable solution to global water shortage, which requires high efficiency, high durability, low cost, and environmentally friendly water collectors. In this paper, we report a novel water collector design based on a nature-inspired hybrid superhydrophilic/superhydrophobic aluminum surface. The surface is fabricated by combining laser and chemical treatments. We achieve a 163° contrast in contact angles between the superhydrophilic pattern and the superhydrophobic background. Such a unique superhydrophilic/superhydrophobic combination presents a self-pumped mechanism, providing the hybrid collector with highly efficient water harvesting performance. Based on simulations and experimental measurements, the water harvesting rate of the repeating units of the pattern was optimized, and the corresponding hybrid collector achieves a water harvesting rate of 0.85 kg m–2 h–1. Additionally, our hybrid collector also exhibits good stability, flexibility, as well as thermal conductivity and hence shows great potential for practical application

Loading Cd_0.5Zn_0.5S Quantum Dots onto Onion-Like Carbon Nanoparticles to Boost Photocatalytic Hydrogen Generation

Carbon dots (C dots, size < 10 nm) have been conventionally decorated onto semiconductor matrixes for photocatalytic H₂ evolution, but the efficiency is largely limited by the low loading ratio of the C dots on the photocatalyst. Here, we propose an inverse structure of Cd_0.5Zn_0.5S quantum dots (QDs) loaded onto the onionlike carbon (OLC) matrix for noble metal-free photocatalytic H₂ evolution. Cd_0.5Zn_0.5S QDs (6.9 nm) were uniformly distributed on an OLC (30 nm) matrix with both upconverted and downconverted photoluminescence property. Such an inverse structure allows the full optimization of the QD/OLC interfaces for effective energy transfer and charge separation, both of which contribute to efficient H₂ generation. An optimized H₂ generation rate of 2018 μmol/h/g (under the irradiation of visible light) and 58.6 μmol/h/g (under the irradiation of 550–900 nm light) was achieved in the Cd_0.5Zn_0.5S/OLC composite samples. The present work shows that using the OLC matrix in such a reverse construction is a promising strategy for noble metal-free solar hydrogen production