penghuang

Two donor–acceptor–acceptor (D–A–A)-type molecules incorporating nitrobenzoxadiazole (NBO) as the A–A block and ditolylamine as the D block bridged through a phenylene (PNBO) and a thiophene (TNBO) spacer were synthesized in a one-step coupling reaction. Their electronic, photophysical, and thermal properties; crystallographic analysis; and theoretical calculations were studied to establish a clear structure–property relationship. The results indicate that the quinoidal character of the thiophene bridge strongly governs the structural features and crystal packings (herringbone vs. brickwork) and thus the physical properties of the compounds. PNBO and TNBO were utilized as electron donors combined with C₇₀ as the electron acceptor in the active layer of vacuum-processed bulk heterojunction small-molecule organic solar cells (SMOSCs). The power conversion efficiency of both PNBO- and TNBO-based OSCs exceeded 5 %. The ease of accessibility of PNBO and TNBO demonstrates the potential for simple and economical synthesis of electron donors in vacuum-processed SMOSCs.

Building bridges! Phenylene- and thiophene-bridged donor–acceptor–acceptor (D–A–A) molecules are synthesized using a one-step coupling reaction. The molecules are used as electron donors for small-molecule organic solar cells, which displayed power conversion efficiencies exceeding 5 %.

We investigate solution-processed low-temperature lead-halide perovskite solar cells employing deoxyribose nucleic acid (DNA)–hexadecyl trimethyl ammonium chloride (CTMA) as the hole-transport layer and (6,6)-phenyl C₆₁-butyric acid methyl ester (PCBM) as electron-acceptor layer in an inverted p–i–n device configuration. The perovskite solar cells utilizing a bio-based charge-transport layer demonstrate power conversion efficiency values of 15.86 %, with short-circuit current density of 20.85 mA cm⁻², open circuit voltage of 1.04 V, and fill factor of 73.15 %, and improved lifetime. DNA-based devices maintained above 85 % of the initial efficiency after 50 days in air.

Bio-derived stability: Deoxyribose nucleic acid (DNA)–hexadecyl trimethyl ammonium chloride (CTMA) as the hole-transport layer in perovskite solar cells shows enhanced device efficiency as well as improved lifetime based on a p–i–n device structure. DNA-based devices exhibit device efficiency over 15 % higher than that of the perovskite solar cells constructed with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and maintained above 85 % of their initial efficiency after 50 days in air.

The incorporation of single cobalt active sites within a graphene matrix leads to a composite material with superior activity and stability when used as a counter electrode for the interconversion of the redox couple I⁻/I₃⁻. In their Communication on page 6708 ff., D. Deng, W.-H. Zhang, and co-workers further show that the use of this material as a counter electrode in a dye-sensitized solar cell (DSSC) leads to a better power conversion efficiency than the use of a platinum counter electrode.

An efficient, stable, and intrinsically safe solar water-splitting device is demonstrated using a III–V tandem junction photoanode, an acid-stable, earth-abundant hydrogen evolution catalyst, and a bipolar membrane. The integrated photoelectrochemical cell operates under a steady-state pH gradient and achieves ≈10% solar-to-hydrogen conversion efficiency, >100 h of stability in a large (>1 cm²) photoactive area in relation to most previous reports.

Highly efficient polymer solar cells with tandem structure are fabricated by using two excellent photovoltaic polymers and a highly transparent intermediate recombination layer. Power conversion efficiencies over 11% can be realized featured by a low-band-gap polymer with fine-tuned properties.