Non-fullerene all-small-molecule organic solar cells (NFSM-OSCs) have shown potential as OSCs, owing to their high purity, easy synthesis and good reproducibility. However, challenges in the modulation of phase separation morphology have limited their development. Herein, two novel small molecular donors, BTEC-1F and BTEC-2F, derived from the small molecule DCAO3TBDTT, are synthesized. Using Y6 as the acceptor, devices based on non-fluorinated DCAO3TBDTT showed an open circuit voltage (Voc) of 0.804 V and a power conversion efficiency (PCE) of 10.64 %. Mono-fluorinated BTEC-1F showed an increased Voc of 0.870 V and a PCE of 11.33 %. The fill factor (FF) of di-fluorinated BTEC-2F-based NFSM-OSC was improved to 72.35 % resulting in a PCE of 13.34 %, which is higher than that of BTEC-1F (61.35 %) and DCAO3TBDTT (60.95 %). To our knowledge, this is the highest PCE for NFSM-OSCs. BTEC-2F had a more compact molecular stacking and a lower crystallinity which enhanced phase separation and carrier transport. 相似文献
Side-chain engineering as one of the most important molecular design strategies has been widely used to improve photovoltaic e什i-ciency of active layer material... 相似文献
In this work, we performed a systematic comparison of different duration of solvent vapor annealing (SVA) treatment upon state-of-the-art PM6:SY1 blend film, which is to say for the first time, the insufficient, appropriate, and over-treatment’s effect on the active layer is investigated. The power conversion efficiency (PCE) of corresponding organic solar cell (OSC) devices is up to 17.57% for the optimized system, surpassing the two counterparts. The properly tuned phase separation and formed interpenetrating network plays an important role in achieving high efficiency, which is also well-discussed by the morphological characterizations and understanding of device physics. Specifically, these improvements result in enhanced charge generation, transport, and collection. This work is of importance due to correlating post-treatment delicacy, thin-film morphology, and device performance in a decent way. 相似文献
Nanostructured polymer‐based solar cells (PSCs) have emerged as a promising low‐cost alternative to conventional inorganic photovoltaic devices and are now a subject of intensive research both in academia and industry. For PSCs to become practical efficient devices, several issues should still be addressed, including further understanding of their operation and stability, which in turn are largely determined by the morphological organisation in the photoactive layer. The latter is typically a few hundred nanometres thick film and is a blend composed of two materials: the bulk heterojunction consisting of the electron donor and the electron acceptor. The main requirements for the morphology of efficient photoactive layers are nanoscale phase segregation for a high donor/acceptor interface area and hence efficient exciton dissociation, short and continuous percolation pathways of both components leading through the layer thickness to the corresponding electrodes for efficient charge transport and collection, and high crystallinity of both donor and acceptor materials for high charge mobility. In this paper, we review recent progress of our understanding on how the efficiency of a bulk heterojunction PSC largely depends on the local nanoscale volume organisation of the photoactive layer.
Organic semiconductors with noncovalently conformational locks (OSNCs) are promising building blocks for hole-transporting materials (HTMs). However, lack of satisfied neighboring building blocks negatively impacts the optoelectronic properties of OSNCs-based HTMs and imperils the stability of perovskite solar cells (PSCs). To address this limitation, we introduce the benzothieno[3,2-b]thiophene (BTT) to construct a new OSNC, and the resulting HTM ZS13 shows improved intermolecular charge extraction/transport properties, proper energy level, efficient surface passivation effect. Consequently, the champion devices based on doped ZS13 yield an efficiency of 24.39 % and 20.95 % for aperture areas of 0.1 and 1.01 cm2, respectively. Furthermore, ZS13 shows good thermal stability and the capability of inhibiting I− ion migration, thus, leading to enhanced device stability. The success in neighboring-group engineering can triggered a strong interest in developing thienoacene-based OSNCs toward efficient and stable PSCs. 相似文献
The semitransparent flexible organic solar cell takes advantages of flexibility, transparency, color adjustment property, which is more conducive to integrate on buildings and mobile terminals. Ascribing to the developments of narrow band gap donors and the new non-fullerene acceptors, the power conversion efficiency of semitransparent flexible organic solar cells has been achieved 10% to 12% with average visible transmittance of 17% to 21%. This review summarizes the molecular design of the most representative active layer materials, and discusses the characterization of semitransparent parameters paradigms, then we discuss how to optimize the device in combination with optical simulation, and finally list the recent development of semitransparent flexible electrodes of ITO-free organic solar cells, and give our perspectives on the next step direction. 相似文献