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For organic solar cells to be competitive, the light-absorbing molecules should simultaneously satisfy multiple key requirements, including weak-absorption charge transfer state, high dielectric constant, suitable surface energy, proper crystallinity, etc. However, the systematic design rule in molecules to achieve the abovementioned goals is rarely studied. In this work, guided by theoretical calculation, we present a rational design of non-fullerene acceptor o-BTP-eC9, with distinct photoelectric properties compared to benchmark BTP-eC9. o-BTP-eC9 based device has uplifted charge transfer state, therefore significantly reducing the energy loss by 41 meV and showing excellent power conversion efficiency of 18.7%. Moreover, the new guest acceptor o-BTP-eC9 has excellent miscibility, crystallinity, and energy level compatibility with BTP-eC9, which enables an efficiency of 19.9% (19.5% certified) in PM6:BTP-C9:o-BTP-eC9 based ternary system with enhanced operational stability.

The electrolysis of aromatic molecules is a useful method for the synthesis and deposition of conducting polymers. However, this method cannot be applied to diverse large‐area electronic devices because films grow vertically on the surface of an electrically connected working electrode. Herein, the remote‐controllable lateral electropolymerization of 3,4‐ethylenedioxythiophene using direct‐current voltage superimposed alternating‐current voltage (ADC)‐bipolar electrochemistry is reported. The use of shape‐designed dual bipolar electrodes and systematic optimization of the process parameters led to the fabrication of uniform poly(3,4‐ethylenedioxythiophene) (PEDOT) films on 2‐inch glass wafers and flexible plastic substrates. The oxidation levels and microstructures of ADC‐electropolymerized PEDOTs with various supporting electrolytes are investigated and correlated with their thermoelectric properties. A soft thermocouple and resistive‐type gas sensor based on an ADC‐electrodeposited PEDOT are demonstrated to monitor cerebral temperature in a brain replica and to sense nitrogen dioxide gas, respectively. [ABSTRACT FROM AUTHOR]

Thermoelectric (TE) charge transport in organic TE nanocomposite systems is a critical consideration in designing high‐performance TE materials. Here, the relationship between the TE properties and energy structure of conducting polymer/quantum dot (QD) nanocomposites is systematically investigated by developing a potential wall or potential well in poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with CdTe QDs. The added QDs are primarily distributed within the electrically insulating PSS shell and act as stepping stones for charge transport between PEDOT‐rich grains. The embedded QDs generate an energy‐filtering effect, which is induced by both potential wall and potential well states established by the QDs in the PEDOT:PSS films. The induced energy‐filtering effect increases the Seebeck coefficient S with limited loss of electrical conductivity σ, thereby overcoming the TE trade‐off relation S ∝ σ−1/4. The energy‐filtering effect is optimized by carefully controlling the QD size. The PEDOT:PSS/QD nanocomposite containing the smallest QDs exhibits a power factor of 173.8 µW m−1 K−2, which is 80% larger than the value for the pristine PEDOT:PSS film. This work suggests a strategy for designing TE nanocomposites with improved TE performance and emphasizes the importance of fine‐tuning the interfacial energy gap to achieve an effective energy‐filtering effect. [ABSTRACT FROM AUTHOR]

Anode interlayers play critical roles in organic solar cells, impacting the electrode's work function, energy level alignment, hole extraction, and electrode surfaces. However, the development of the commonly used anode interlayer PEDOT:PSS lags behind the rapid development of organic solar cells due to its low conductivity, acidity, and poor electron‐blocking capabilities. Herein, an innovative strategy is proposed to regulate the intrinsic properties of PEDOT:PSS by incorporating molybdenum‐containing semiconductors (MoO3, MoS2), which is validated using the state‐of‐the‐art active layer consisting of PM6:Y6 in conventional devices. The addition of molybdenum‐containing semiconductors alters the aggregation morphology of the PEDOT:PSS layer, increasing its conductivity and reducing its acidity. Furthermore, the hole extraction and electron‐blocking ability are improved by changing the work function of the anode with the influence of the deep energy level and by forming a trap energy level to capture electrons. Consequently, when the interlayer is employed, a champion power conversion efficiency of 17.1% in the PM6:Y6 devices and 18.9% in organic solar cells composed of PM6:L8‐BO is achieved. The results, which enhance the intrinsic properties of PEDOT:PSS with molybdenum‐containing semiconductors, offer valuable guidelines for engineering anode interlayers to fabricate highly efficient non‐fullerene organic solar cells. [ABSTRACT FROM AUTHOR]

The water surface provides a highly effective platform for the synthesis of two-dimensional polymers (2DP). In this study, we present an efficient on-water surface synthesis of crystalline monolayer 2D polyimide (2DPI) through the imidization reaction between tetra (4-aminophenyl) porphyrin (M1) and perylenetracarboxylic dianhydride (M2), resulting in excellent stability and coverage over a large area (tens of cm2). We further fabricate innovative organic-inorganic hybrid van der Waals heterostructures (vdWHs) by combining with exfoliated few-layer molybdenum sulfide (MoS2). High-resolution transmission electron microscopy (HRTEM) reveals face-to-face stacking between MoS2 and 2DPI within the vdWH. This stacking configuration facilitates remarkable charge transfer and noticeable n-type doping effects from monolayer 2DPI to MoS2, as corroborated by Raman spectroscopy, photoluminescence measurements, and field-effect transistor (FET) characterizations. Notably, the 2DPI-MoS2 vdWH exhibits an impressive electron mobility of 50 cm2/V·s, signifying a substantial improvement over pristine MoS2 (8 cm2/V·s). This study unveils the immense potential of integrating 2D polymers to enhance semiconductor device functionality through tailored vdWHs, thereby opening up exciting new avenues for exploring unique interfacial physical phenomena. The water surface has recently proven to be an effective platform for the synthesis of large-area two-dimensional polymers with high crystallinity. Here, the authors report the on-water synthesis of a crystalline monolayer 2D polyimide, as well as its incorporation into organic–inorganic hybrid van der Waals heterostructures that display significant charge transfer and high electron mobility. [ABSTRACT FROM AUTHOR]

Rubbing‐induced alignment of conjugated polymers is systematically investigated in terms of intra‐ and inter‐molecular interaction. Various polymer films with a broad range of polymer chain rigidity are rubbed, and the degree of polymer chain alignment is quantitatively characterized. The rubbing technique effectively aligns crystalline domains in conjugated polymer films when the temperature approaches the critical rubbing temperature (Trc$T_{\mathrm{r}}^{\mathrm{c}}$), at which the rearrangement and the slip of polymer chains are possible. A polymer with significant intra‐/inter‐molecular interactions exhibits higher Trc$T_{\mathrm{r}}^{\mathrm{c}}$, though quantitative analysis reveals an intermediately aligned state at temperature Tr′ lower than Trc$T_{\mathrm{r}}^{\mathrm{c}}$. This state originates from polymer chain aggregation in an amorphous domain. The intermediately aligned state can be controlled by plasticizer, which enables low‐temperature alignment of high‐mobility polymer film by reducing Tr′ to near 100 °C, increases the crystallinity, and improves the alignment effect at this state comparable to that of the completely aligned state obtained at extremely high temperatures. [ABSTRACT FROM AUTHOR]