Zhuping Fei

The performance and reliability of n‐type organic field‐effect transistors (OFETs) are strongly influenced by the interplay between semiconductor crystallinity and the metal/semiconductor interface. Here, we systematically investigate a series of diketopyrrolopyrrole (DPP)‐based n‐type polymers with identical backbones but varying side‐chain architectures, resulting in varied long‐range order. By comparing devices fabricated with conventional Au and low‐work‐function Al/Ti electrodes, we elucidate the synergistic effects of intrinsic polymer crystallinity and interfacial energetics on charge injection, transport, and operational stability. Temperature‐dependent electrical measurements and trap analyses demonstrate that contact resistance, rather than intrinsic bulk transport, dominates the observed mobility differences between polymers of moderate and high crystallinity. Optimized Al/Ti contacts mitigate these interfacial limitations, enabling a transition from contact‐limited to channel‐limited transport and significantly improving environmental and operational stability. These findings establish a quantitative framework linking crystalline order, injection efficiency, and device reliability. This framework provides critical design guidelines for the evaluation and optimization of high‐performance n‐type organic semiconductors.

The synergistic effect of elongated exciton transport and strong exciton-CT state coupling facilitates the generation of long-lived reactive charges in NIR organic photocatalysts.

Fluorination position is critical for defining the photostability of high-performance PBDB-T organic photovoltaic polymers.

A single organic semiconductor typically struggles with inefficient intrinsic charge generation due to large binding energy ( E _B ≈ 0.5 electron volts) of Frenkel excitons, particularly in narrow-bandgap organic semiconductors that exhibit near-infrared (NIR) absorption. Here, we develop double-cable polymer–based nanoparticles (NPs), enabling single-component organic photocatalysts to achieve NIR photon absorption and generate long-lived free charges simultaneously. as -DCPIC, a double-cable polymer with donor polymer (PBDB-T) as electron-donating conjugated backbones and pendent NIR acceptor (TPDIC) as the electron-deficient side chains, offers potential for self-sustained photoelectric conversion. Consequently, as -DCPIC NPs exhibit significantly enhanced hydrogen evolution performance (11.88 mmol per hour per gram) compared to pristine PBDB-T or TPDIC NPs. Transient absorption spectroscopy elucidates the effective electron-hole separation inside as -DCPIC NPs, whereas decay kinetics monitor the long-lived free carriers (109 nanoseconds) in as -DCPIC NPs. Our findings demonstrate that double-cable polymers provide a powerful platform for establishing efficient single-component organic photocatalysts to generate long-lived reactive charges.

Incorporating boron atoms into organic macrocycles imparts unique chemical, electronic, and optical properties. The concept of making use of dative boron-nitrogen (B ← N) bonds for the construction of macrocycles has been proposed, but very few examples have been prepared with functional structures, much less pillar-like and other prismatic macrocycles, and their various functionalities have not been fully exploited. Here, we introduce a "functional molecular wall" synthetic protocol based on the self-assembly characteristics of B ← N dative bonds to construct highly symmetrical macrocycles, forming a quasi-pentagonal-shaped macrocycle (named [5]pyBN-p) with a pillar-like structure. Single-crystal analysis confirmed that its structure exhibited a 5-fold symmetric crown-shaped cavity with a diameter of approximately 9.65 Å, forming four sets of three-dimensional channel stacking structures. In solution, thermal cycling between heating and cooling allows for a fast and fully reversible conversion between monomer pyBN-p and pentameric macrocycle [5]pyBN-p. The resultant macrocycle [5]pyBN-p exhibited delayed fluorescence (DF) property and high photoluminescence quantum yield in the solid state. Notably, the supramolecular aggregates of macrocycle [5]pyBN-p possessed permanent porosity and showed an efficient C₂H₆/C₂H₄ inverse separation capacity. This work highlights a new molecular design strategy for B ← N-containing macrocycles, enriching the family of molecular species and expanding new avenues for their applications.

Nearly amorphous conjugated polymers, though lacking long‐range order, can exhibit high charge carrier mobility and enhanced flexibility, making them ideal for flexible or stretchable OFET applications. However, research on novel structural blocks for this class of materials remains limited. We report the synthesis of two derivatives of the 5,10‐dihydroindeno[2,1‐ a ]indene (DHI) core, where two thieno groups are appended to each end to reduce torsional disorder with adjacent comonomers. The two 1,4‐dihydropentalene containing isomers, anti‐C16DHIT‐Br and syn‐C16DHIT‐Br, feature distinct thieno group orientations, leading to differences in their electronic properties. The anti‐isomer shows a fully delocalized conjugation pathway, whereas the syn isomer exhibits cross‐conjugation, limiting delocalization along the polymer backbone. These monomers were copolymerized with benzothiadiazole (BT) to form two conjugated polymers, anti‐C16DHIT‐BT and syn‐C16DHIT‐BT, both with highly planar backbones, good solubility, and solution processability. Morphological studies reveal that anti‐C16DHIT‐BT exhibits more ordered stacking and higher crystallinity than syn‐C16DHIT‐BT. Devices based on anti‐C16DHIT‐BT show significantly better performance, with a hole mobility of 2.38 cm ² V ⁻¹ s ⁻¹ , slightly higher than the widely studied pIDTBT under identical conditions.