H‐Bonds‐Assisted Molecular Order Manipulation of Nonfullerene Acceptors for Efficient Nonannealed Organic Solar Cells

Abstract

Various substituents have been incorporated into nonfullerene acceptors (NFAs) to modulate absorption scopes and energy levels for boosting efficiencies of organic solar cells (OSCs). The manipulation of the NFAs' molecular order and crystallinity via those substitutions is equally crucial to OSC performances, which yet remains interesting and challenging. The hydroxyl group, which can potentially form strong intermolecular hydrogen bonds (H‐bonds) for improving molecular arrangements, has, however, never been considered. Herein, two hydroxyl‐functionalized NFAs, IT‐OH with one hydroxyl and IT‐DOH with two hydroxyls, are synthesized to tune the molecular packing and crystallinity. The ordered molecular arrangement and higher crystallinity are observed for the IT‐OH and IT‐DOH than the parent ITIC. This is assigned to the formation of intermolecular H‐bonds induced by the hydroxyls, which elongates molecular conjugated planes leading to long‐range‐ordered structures via π–π stacking. By the appropriate crystallinity and miscibility with donor polymer, an IT‐DOH‐based nonannealed OSC affords an efficiency of 12.5% with good device stability. This work provides a promising strategy to tune the molecular packing and crystallinity to design NFAs by introducing hydroxyl groups.

Structural Strategies for Germanium‐Based Anode Materials to Enhance Lithium Storage

“…The hollow cubes Ge/C hybrid displayed a Li reversible storage capacity of 1336 mAh g −1 at a current density of 200 mA g −1 after 150 cycles. In another work, Ge@carbon cubes (Ge@CC) due to the unique cubic core–shell structure and the effective carbon coating, delivered capacity of 497 mAh g −1 at a current rate of 30 C and showed excellent cycling stability of 1065.2 mAh g −1 at 0.5 C for over 500 cycles . With the similar design, hollow ellipsoidal Ge@C exhibited a capacity of 1285 mAh g −1 after 200 cycles at 0.2 C with no capacity fading, and higher rate capability of 805 mAh g −1 at 20 C 25b.…”

Initial Properties Identification of Refined- and Semi Refined-Carrageenans as Raw Materials for Biodegradable Plastic Production

“…This may explain the higher crystallinity of the RC sample described previously in Figure 1. A high amount of hydroxyl groups in the RC intermolecular structure imparts its strong molecular packing and crystallinity through the hydrogen bonds (Liu et al, 2020). On the other hand, intensity for the stretching band peaked at 1424 cm -1 ascribed to the C-O-C asymmetric bonding of cellulose.…”

Small bandgap non-fullerene acceptor enables efficient PTB7-Th solar cell with near 0 eV HOMO offset

“…In this work, we used a carbon-oxygen bridged ladder type building block [31][32][33][34][35][36][37][38][39][40][41][42] as the electron-donating core, octyl thieno [3,4-b ]thiophene-2-carboxylate as the π bridge with (dicyanomethylene)indent-1-one (INCN) end-caps to construct three NFAs, BDTI, BDTI-2F and BDTI-4F, difference on the number of substituted fluorine atoms at INCN. All NFAs possess broad absorption extended to near 10 0 0 nm wavelength.…”