Heterogeneous dissociation process of truncated RNAs by oligomerized Vasa helicase

RNA helicases are enzymes that generally unwind double-stranded RNA using ATP hydrolysis energy, mainly involved in RNA metabolism, transcription, translation, and mRNA splicing. While the helicase core is crucial for RNA unwinding activity, N- and C-terminal extensions of specific helicases may contain an intrinsically disordered region for electrostatic interaction, resulting in the formation of droplets in the cytoplasm. However, how the disordered region of the RNA helicase contributes to RNA unwinding and dissociation remains unclear. Here, we focused on Bombyx mori Vasa, which unwinds truncated target transposon RNAs from the piRNA-induced silencing complex piRISC. In this study, we used single-molecule techniques to visualise how Vasa dynamically interacts with piRISC and investigate how Vasa oligomerization is involved in the process of piRNA amplification, named the ping-pong pathway. We found that Vasa’s oligomerization is required during these processes in vitro and in vivo, and that Vasa triggers the dissociation of truncated RNA in heterogeneous pathways. Our single-molecule results suggest that oligomerized Vasa guides the timing of the process regulating overall dissociation efficiency.

Understanding of Photophysical Processes in DIO Additive-Treated PTB7:PC71BM Solar Cells

1,8-diiodooctane (DIO) additive is an important method for optimizing the morphology and device performance of polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7)-based polymer solar cells. However, the effect of DIO additive on charge photogeneration dynamics of PTB7-based polymer solar cells is still poorly understood. In this work, the effect of DIO additive on the carrier photogeneration dynamics, as well as device performance of PTB7: [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) solar cells was studied. Bias-dependent photoluminescence (PL) experiments of a neat PTB7 device show that the exciton cannot be dissociated by the electric field in the device within the operating voltage range, but it can be effectively dissociated by the high electric field. PL and time-resolved PL studies show that DIO additive reduces the phase size of PTB7 in the blend film, resulting in an increased exciton dissociation efficiency. The carrier recombination processes were studied by transient absorption, which shows geminate carrier recombination was suppressed in the DIO-treated PTB7:PC71BM device in ultrafast time scale. The increased exciton dissociation efficiency and suppressed carrier recombination in ultrafast time scale play an important role for DIO-treated PTB7:PC71BM solar cells to attain a higher power conversion efficiency.

Diffusion-enhanced exciton dissociation in single-material organic solar cells

Multiple crossings at the domain boundary with different molecular orientations enhance the exciton dissociation efficiency in single-material organic solar cells.

Effect of Post-Thermal Annealing on the Performance and Charge Photogeneration Dynamics of PffBT4T-2OD/PC71BM Solar Cells

In this work, we studied influence of post thermal annealing on the performance and charge photogeneration processes of PffBT4T-2OD/PC71BM solar cells. As-prepared device exhibits a high-power conversion efficiency of 9.5%, much higher than that after thermal annealing. To understand this phenomenon, we studied charge photogeneration processes in these solar cells by means of time resolved spectroscopy. We associate the degradation of solar cell performance with the reduction of exciton dissociation efficiency and with increased bimolecular recombination of photogenerated charges as a result of annealing. We correlate the generation of localized PffBT4T-2OD polarons observed via spectro-electrochemical measurements with enhancement of the bimolecular charge recombination of annealed solar cells.

Two-dimensional black phosphorous induced exciton dissociation efficiency enhancement for high-performance all-inorganic CsPbI3 perovskite photovoltaics

An effective strategy to enhance the exciton dissociation efficiency in inorganic perovskites is reported by incorporating layer-structure-tunable two-dimensional black phosphorous.

Effects of CH3NH3PbI(3-x)Clx Perovskite Layer on the Performance of Inverted Type Hybrid Organic Solar Cells Based on ZnO/P3HT

This paper reports the effect of perovskite layer on enhancing the inverted type hybrid organic solar cell performance. The mixtures of methylammonium iodide (CH3NH3I) and lead (II) chloride (PbCl2) were dissolved in N,N-Dimethylformamide (DMF) solvent and was spin-coated onto fluorine-doped tin oxide (FTO) glass substrate coated with zinc oxide nanorod arrays (ZnONRAs). The poly (3-hexylthiophene-2,5-diyl) (P3HT) film was then spin-coated onto CH3NH3I(3-x)PbClx perovskite layer, followed by silver (Ag) deposition using magnetron sputtering technique. The FTO/ZnO seed/ZnONRAs/CH3NH3PbI(3-x)Clx /P3HT/Ag device was fabricated. A device without perovskite layer was also fabricated for comparison. A power conversion efficiency (PCE) of 0.56% was achieved with the introduction of perovskite layer. The PCE was approximately six times greater than the device without perovskite layer, as a result of wider light absorption range and higher exciton dissociation efficiency.