Yongqiang Shi

Self‐assembled monolayers as hole‐transport materials have been a milestone in the advancement of inverted perovskite solar cells (PSCs). However, its strong‐acidity and weak‐interface‐bonding inherences remain great challenges for commercially desirable PSCs. To overcome the limitation, we proposed the orientation‐engineered interfacial bi‐anchoring molecules with a symmetric linear donor–acceptor–donor (D–A–D) structured N‐oxide‐based building block. The D–A–D structure with intramolecular push–pull electron effects features superior hole‐selective ability than the widely used donor units, endowing effective hole‐transport planar. However, the bilateral N‐oxide functional groups (N ⁺ ‐O ⁻ ) in the acceptor bipyridine introduce a steric effect to drive the D–A–D planar in both in‐plane and out‐of‐plane directions, effectively promoting the hole extraction. Moreover, the reversely oriented N ⁺ ‐O ⁻ function groups can firmly adsorb on ITO substrate and perovskite buried surface, respectively, constructing an interfacial bi‐anchoring connection. This molecular configuration considerably promotes the photothermal tolerance, connective strength as well as energy‐level alignment at perovskite/HTLs interface, enabling superior charge extraction and durability. Consequently, BPyDO‐TPA‐based inverted PSCs achieve an impressive efficiency of 26.53%, ranking as one of the highest efficiencies among nonphosphonic acid small‐molecule transporting materials. BPyDO‐TPA‐based devices also demonstrate excellent operational stability, retaining 94.82% of its initial efficiency after MPP tracking for 1000 h at 85 °C.

Self‐assembled monolayers as hole‐transport materials have been a milestone in the advancement of inverted perovskite solar cells (PSCs). However, its strong‐acidity and weak‐interface‐bonding inherences remain great challenges for commercially desirable PSCs. To overcome the limitation, we proposed the orientation‐engineered interfacial bi‐anchoring molecules with a symmetric linear donor–acceptor–donor (D–A–D) structured N‐oxide‐based building block. The D–A–D structure with intramolecular push–pull electron effects features superior hole‐selective ability than the widely used donor units, endowing effective hole‐transport planar. However, the bilateral N‐oxide functional groups (N ⁺ ‐O ⁻ ) in the acceptor bipyridine introduce a steric effect to drive the D–A–D planar in both in‐plane and out‐of‐plane directions, effectively promoting the hole extraction. Moreover, the reversely oriented N ⁺ ‐O ⁻ function groups can firmly adsorb on ITO substrate and perovskite buried surface, respectively, constructing an interfacial bi‐anchoring connection. This molecular configuration considerably promotes the photothermal tolerance, connective strength as well as energy‐level alignment at perovskite/HTLs interface, enabling superior charge extraction and durability. Consequently, BPyDO‐TPA‐based inverted PSCs achieve an impressive efficiency of 26.53%, ranking as one of the highest efficiencies among nonphosphonic acid small‐molecule transporting materials. BPyDO‐TPA‐based devices also demonstrate excellent operational stability, retaining 94.82% of its initial efficiency after MPP tracking for 1000 h at 85 °C.

Developing high-performance n-type polymer semiconductors is hindered by the scarcity of strong electron-deficient building blocks. Herein, we report a dual-functionalization strategy that integrates both quinoid and cyano groups into polythiophene backbones to construct n-type polymers. Two new polymers, PQTTCN and PQTVTCN, were synthesized via the Stille copolymerization of a thienoquinoid-based dibrominated monomer (TTD2T-Br) with cyano-functionalized bithiophene and thienylene-vinylene-thienylene distannyl monomers, respectively. Electrochemical and computational analyses confirm that both polymers exhibit low-lying LUMO levels of −4.07 eV and highly planar backbones. In organic field-effect transistors, PQTTCN and PQTVTCN show unipolar n-type charge transport, with electron mobilities of 0.036 and 0.002 cm² V⁻¹ s⁻¹, respectively, which are attributed to their deep frontier molecular orbitals and planar conformations. Upon doping, both polymers exhibit n-type thermoelectric performance, achieving an electrical conductivity and power factor values of 0.16 S cm⁻¹ and 0.75 μW m⁻¹ K⁻² for PQTTCN and 0.043 S cm⁻¹ and 0.17 μW m⁻¹ K⁻² for PQTVTCN, respectively. AFM and GIWAXS results demonstrate that PQTTCN has better dopant compatibility and higher crystallinity than PQTVTCN. This work highlights that the combination of quinoid and cyano units offers a promising strategy for developing high-performance n-type polymer semiconductors for organic electronics.

Solid additives have emerged as a widely adopted strategy in organic solar cells (OSCs) due to their efficacy in modulating the film morphology and regulating the aggregation behavior of the photoactive layer, which is crucial for achieving high power conversion efficiencies (PCEs). However, the chemical structure of these solid additives fundamentally dictates their performance. Herein, we designed two isomeric solid additives, syn ‐dithieno[2,3‐ b :3',2'‐ e ]pyrazine ( syn ‐DTPy) and anti ‐dithieno[2,3‐ b :2',3' ‐e ]pyrazine ( anti ‐DTPy), to enhance OSCs’ performance. When incorporated into the D18:L8‐BO system, anti ‐DTPy establishes directional intermolecular interactions that optimize phase separation and charge transport pathways. This approach enabled OSCs to achieve a remarkable PCE of 20.5%, with a high fill factor (FF) of 81.9%, ranking among the highest reported values. This study reveals a distinct isomer‐dependent conformational effect for morphology control, providing profound insights into structure‐property relationships and guiding the design of advanced solid additives.

Solid additives have emerged as a widely adopted strategy in organic solar cells (OSCs) due to their efficacy in modulating the film morphology and regulating the aggregation behavior of the photoactive layer, which is crucial for achieving high power conversion efficiencies (PCEs). However, the chemical structure of these solid additives fundamentally dictates their performance. Herein, we designed two isomeric solid additives, syn ‐dithieno[2,3‐ b :3',2'‐ e ]pyrazine ( syn ‐DTPy) and anti ‐dithieno[2,3‐ b :2',3' ‐e ]pyrazine ( anti ‐DTPy), to enhance OSCs’ performance. When incorporated into the D18:L8‐BO system, anti ‐DTPy establishes directional intermolecular interactions that optimize phase separation and charge transport pathways. This approach enabled OSCs to achieve a remarkable PCE of 20.5%, with a high fill factor (FF) of 81.9%, ranking among the highest reported values. This study reveals a distinct isomer‐dependent conformational effect for morphology control, providing profound insights into structure‐property relationships and guiding the design of advanced solid additives.

Developing simple and effective molecular design strategies to optimize charge transport mobility remains a key challenge in high‐performance organic semiconductors. In this study, we integrate hydrogen bonding (H‐B) and ring‐fusion (R‐F) into a diketopyrrolopyrrole (DPP)‐based polymer, yielding a novel material, P‐HF. For comparison, a reference polymer (P‐B) and a hydrogen‐bonded analogue (P‐H) were synthesized. The synergistic effects of H‐B and R‐F dramatically not only enhance both inter‐ and intramolecular charge transport but also optimize the frontier orbital levels; H‐B strengthens intermolecular interactions, enabling localized ordered molecular packing and tighter π–π stacking, while R‐F further amplifies these effects meanwhile improving backbone planarity, extending π‐conjugation, and optimizing frontier orbital levels. As a result, P‐HF achieves an outstanding hole mobility of 5.02 cm ² V ⁻¹ s ⁻¹ , surpassing P‐B (0.71 cm ² V ⁻¹ s ⁻¹ ) and P‐H (2.13 cm ² V ⁻¹ s ⁻¹ ), placing it among the highest‐performing DPP‐based polymers reported. This work demonstrates that combining R‐F and H‐B offers a viable strategy for designing high‐mobility conjugated materials, potentially advancing organic semiconductor development. This dual‐engineering strategy is particularly suitable for π‐conjugated polymers containing both hydrogen‐bonding sites and ring‐fused backbones.

Developing simple and effective molecular design strategies to optimize charge transport mobility remains a key challenge in high‐performance organic semiconductors. In this study, we integrate hydrogen bonding (H‐B) and ring‐fusion (R‐F) into a diketopyrrolopyrrole (DPP)‐based polymer, yielding a novel material, P‐HF. For comparison, a reference polymer (P‐B) and a hydrogen‐bonded analogue (P‐H) were synthesized. The synergistic effects of H‐B and R‐F dramatically not only enhance both inter‐ and intramolecular charge transport but also optimize the frontier orbital levels; H‐B strengthens intermolecular interactions, enabling localized ordered molecular packing and tighter π–π stacking, while R‐F further amplifies these effects meanwhile improving backbone planarity, extending π‐conjugation, and optimizing frontier orbital levels. As a result, P‐HF achieves an outstanding hole mobility of 5.02 cm ² V ⁻¹ s ⁻¹ , surpassing P‐B (0.71 cm ² V ⁻¹ s ⁻¹ ) and P‐H (2.13 cm ² V ⁻¹ s ⁻¹ ), placing it among the highest‐performing DPP‐based polymers reported. This work demonstrates that combining R‐F and H‐B offers a viable strategy for designing high‐mobility conjugated materials, potentially advancing organic semiconductor development. This dual‐engineering strategy is particularly suitable for π‐conjugated polymers containing both hydrogen‐bonding sites and ring‐fused backbones.

Using a “two birds with one stone” design, we devised the electron deficient monomers BTPD BTz and BTPD TTz and polymerized them via direct C–H arylation. Upon n doping, the resulting polymers achieved an electrical conductivity of 7.91 S cm⁻¹.

A novel side chain grafted non-conjugated polymer acceptor (SPA-1) was designed and synthesized. The SPA-1 based All-PSC showed a promising PCE of 11.16%, comparable to most All-PSCs using non-conjugated copolymer acceptors.