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AbstractOrganic solar cells based on semiconducting polymers and small molecules have attracted considerable attention in the last two decades. Moreover, the power conversion efficiencies for solution‐processed solar cells containing A–π–D–π–A‐type small molecules and fullerenes have reached 11%. However, the method for designing high‐performance, photovoltaic small molecules still remains unclear. In this review, recent studies on A–π–D–π–A electron‐donating small molecules for organic solar cells are introduced. Moreover, the relationships between molecular properties and device performances are summarized, from which inspiration for the future design of high performance organic solar cells may be obtained.

AbstractOrganic solar cells based on semiconducting polymers and small molecules have attracted considerable attention in the last two decades. Moreover, the power conversion efficiencies for solution‐processed solar cells containing A–π–D–π–A‐type small molecules and fullerenes have reached 11%. However, the method for designing high‐performance, photovoltaic small molecules still remains unclear. In this review, recent studies on A–π–D–π–A electron‐donating small molecules for organic solar cells are introduced. Moreover, the relationships between molecular properties and device performances are summarized, from which inspiration for the future design of high performance organic solar cells may be obtained.

A 2D–3D perovskite, in which 3D perovskite phase is bridged by 2D perovskite having periodically repeated vertical orientation is reported. It's PCE and stability is better than 3D MAPbI3 and it is an excellent structural strategy to improve stability of perovskite solar cells.

A 2D–3D perovskite, in which 3D perovskite phase is bridged by 2D perovskite having periodically repeated vertical orientation is reported. It's PCE and stability is better than 3D MAPbI3 and it is an excellent structural strategy to improve stability of perovskite solar cells.

All‐small‐molecule organic solar cells have attracted great interests due to their well‐defined molecular structures and suitability for investigating the relationship between the structure and properties. Herein, two small‐molecule donors (SMDs) based on DTBDT core with chlorine atoms and alkylsilyl side chains, namely, ZR‐Si3 and ZR‐Si4, are synthesized and their respective photovoltaic properties by blending them with IDIC‐4Cl and Y6 are studied. The power conversion efficiency (PCE) based on IDIC‐4Cl is higher than that of Y6 systems due to low driving force between the donors and Y6. Although the two IDIC‐4Cl systems have similar morphology, the PCE of 10.10% is attained based on ZR‐Si4, which is higher than that of ZR‐Si3‐based devices (8.12%). To obtain an in‐depth insight into the structure and performance relationship, single crystals of two SMDs and acceptors are obtained successfully. The shortest π−π stacking distance of 3.43 Å and a transport channel between the layers are observed for ZR‐Si4, which is beneficial for getting better performance.

All‐small‐molecule organic solar cells have attracted great interests due to their well‐defined molecular structures and suitability for investigating the relationship between the structure and properties. Herein, two small‐molecule donors (SMDs) based on DTBDT core with chlorine atoms and alkylsilyl side chains, namely, ZR‐Si3 and ZR‐Si4, are synthesized and their respective photovoltaic properties by blending them with IDIC‐4Cl and Y6 are studied. The power conversion efficiency (PCE) based on IDIC‐4Cl is higher than that of Y6 systems due to low driving force between the donors and Y6. Although the two IDIC‐4Cl systems have similar morphology, the PCE of 10.10% is attained based on ZR‐Si4, which is higher than that of ZR‐Si3‐based devices (8.12%). To obtain an in‐depth insight into the structure and performance relationship, single crystals of two SMDs and acceptors are obtained successfully. The shortest π−π stacking distance of 3.43 Å and a transport channel between the layers are observed for ZR‐Si4, which is beneficial for getting better performance.

The treatment of toluene solvent and DTT additive enables the PBQ6:PYF-T-o-based all-PSC devices with PCE up to 17.06%, which is one of the highest value in non-halogenated-processed all-PSCs to date.

The treatment of toluene solvent and DTT additive enables the PBQ6:PYF-T-o-based all-PSC devices with PCE up to 17.06%, which is one of the highest value in non-halogenated-processed all-PSCs to date.

The investigation of the surface energy parameters of photovoltaic materials highlights the wetting coefficient as a dominant dynamic for spontaneous Voc gain.