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Tin‐lead (Sn‐Pb) perovskite solar cells (PSCs) have gained interest as candidates for the bottom cell of all‐perovskite tandem solar cells due to their broad absorption of the solar spectrum. A notable challenge arises from the prevalent use of the hole transport layer, PEDOT:PSS, known for its inherently high doping level. This high doping level can lead to interfacial recombination, imposing a significant limitation on efficiency. Herein, NaOH is used to dedope PEDOT:PSS, with the aim of enhancing the efficiency of Sn‐Pb PSCs. Secondary ion mass spectrometer profiles indicate that sodium ions diffuse into the perovskite layer, improving its crystallinity and enlarging its grains. Comprehensive evaluations, including photoluminescence and nanosecond transient absorption spectroscopy, confirm that dedoping significantly reduces interfacial recombination, resulting in an open‐circuit voltage as high as 0.90 V. Additionally, dedoping PEDOT:PSS leads to increased shunt resistance and high fill factor up to 0.81. As a result of these improvements, the power conversion efficiency is enhanced from 19.7% to 22.6%. Utilizing NaOH to dedope PEDOT:PSS also transitions its nature from acidic to basic, enhancing stability and exhibiting less than a 7% power conversion efficiency loss after 1176 h of storage in N2 atmosphere. [ABSTRACT FROM AUTHOR]

A universal approach for enhancing water affinity in polymer photocatalysts by covalently attaching hydrophilic photocrosslinkers to polymer chains is presented. A series of bisdiazirine photocrosslinkers, each comprising bisdiazirine photophores linked by various aliphatic (CL‐R) or ethylene glycol‐based bridge chains (CL‐TEG), is designed to prevent crosslinked polymer photocatalysts from degradation through a safe and efficient photocrosslinking reaction at a wavelength of 365 nm. When employing the hydrophilic CL‐TEG as a photocrosslinker with polymer photocatalysts (F8BT), the hydrogen evolution reaction (HER) rate is considerably enhanced by 2.5‐fold compared to that obtained using non‐crosslinked F8BT photocatalysts, whereas CL‐R‐based photocatalysts yield HER rates comparable to those of non‐crosslinked counterparts. Photophysical analyses including time‐resolved photoluminescence and transient absorption measurements reveal that adding CL‐TEG accelerates exciton separation, forming long‐lived charge carriers. Additionally, the in‐depth study using molecular dynamics simulations elucidates the dual role of CL‐TEG: it enhances water penetration into the polymer matrix and stabilizes charge carriers after exciton generation against undesirable recombination. Therefore, the strategy highlights endowing a high‐permittivity environment within polymer photocatalyst in a controlled manner is crucial for enhancing photocatalytic redox reactivity. Furthermore, this study shows that this hydrophilic crosslinker approach has a broad applicability in general polymer semiconductors and their nanoparticulate photocatalysts. [ABSTRACT FROM AUTHOR]

We present highly efficient indoor organic photovoltaic (IOPV) devices based on a series of four wide-bandgap random copolymers, denoted as B30T70-XCl (X = 0, 2, 4 and 6). The absorption range of these copolymers efficiently covers the spectral range of indoor light sources, with a systematic decrease in the HOMO levels based on the number of chlorine atoms (0 > 2 > 4 > 6Cl). The introduction of Cl is an effective and cost-efficient strategy because of the simplicity of the synthesis. We use PC71BM as the electron acceptor, which not only effectively absorbs indoor light spectra, but also significantly reduces production costs compared with state-of-the-art non-fullerene acceptors (NFAs). Among the B30T70-XCl:PC71BM blends, the B30T70-2Cl-based devices exhibit optimized power conversion efficiencies (PCEs) with a high VOC, achieving a record-breaking PCE of 25.0% under fluorescent lamp (FL) illumination, compared with reported fullerene-based IOPVs. Through a comprehensive analysis of the energy levels, transient absorption dynamics, and blend morphology, we reveal that increasing the Cl density decreases the HOMO offset between the polymer donors and the PC71BM acceptor and induces a phase-separated blend morphology, critically impacting the performance of IOPVs by influencing the population of charge-separated states and charge transport behavior, respectively. The performance of these IOPVs based on wide-bandgap random copolymers and the PC71BM acceptor suggests that the development of such classical, low-cost photoactive layer blends holds promise for integration into low-power portable electronics and Internet-of-Things (IoT) sensors. [ABSTRACT FROM AUTHOR]

Despite recent advances in colloidal quantum dot (CQD) photovoltaics, several challenges persist and hinder further improvements. In particular, the Fermi level mismatch between the iodide‐treated photoactive and thiol‐treated hole‐transporting CQD layers creates an unfavorable energy band for hole collection. Furthermore, the numerous surface cracks in the thiol‐treated CQD layer facilitate direct contact between the photoactive CQD layer and the metal electrode, consequently leading to reduced device performance. To address these issues, a polycatechol functionalized MXene (PCA‐MXene) that can serve both as a dopant and an interlayer for CQD photovoltaics is developed. By achieving a uniformly dispersed mixture in a butylamine solvent, PCA‐MXene enables the effective combination of MXene and CQDs. This results in the modification of the work function of CQDs and the modulation of the energy band alignment, ultimately promoting enhanced hole extraction. Moreover, the PCA‐MXene employed as an interlayer effectively covers the surface cracks present in the thiol‐treated CQD layer. This coverage inhibits both metal electrode penetration and moisture intrusion into the device. Owing to these advantages, the CQD photovoltaics incorporating PCA‐MXene achieve a power conversion efficiency (PCE) of 13.6%, accompanied by enhanced thermal stability, in comparison to the reference device with a PCE of 12.8%. [ABSTRACT FROM AUTHOR]

In this study, we present a comprehensive investigation into the charge generation mechanism in bulk-heterojunction organic solar cells employing non-fullerene acceptors (NFAs) both with and without the presence of processing additives. While photovoltaic devices based on Y6 or BTP-eC9 have shown remarkable power conversion efficiencies, the underlying charge generation mechanism in polymer:NFA blends remains poorly understood. To shed light on this, we employ transient absorption (TA) spectroscopy to elucidate the charge transfer pathway within a blend of the donor polymer PM6 and NFAs. Interestingly, the charge carrier lifetimes of neat Y6 and BTP-eC9 are comparable, both reaching up to 20 ns. However, the PM6:BTP-eC9 blend exhibits substantially higher charge carrier generation and a longer carrier lifetime compared to PM6:Y6 blend films, leading to superior performance. By comparing TA data obtained from PM6:Y6 or PM6:BTP-eC9 blend films with and without processing additives, we observe significantly enhanced charge carrier generation and prolonged charge carrier lifetimes in the presence of these additives. These findings underscore the potential of manipulating excited species as a promising avenue for further enhancing the performance of organic solar cells. Moreover, this understanding contributes to the advancement of NFA-based systems and the optimization of charge transfer processes in polymer:NFA blends. [ABSTRACT FROM AUTHOR]

Natural photosynthetic systems require spatiotemporal organization to optimize photosensitized reactions and maintain overall efficiency, involving the hierarchical self‐assembly of photosynthetic components and their stabilization through synergistic interactions. However, replicating this level of organization is challenging due to the difficulty in efficiently communicating supramolecular nano‐assemblies with nanoparticles or biological architectures, owing to their dynamic instability. Herein, we demonstrate that the supramolecular reconstruction of self‐assembled amphiphilic rhodamine B nanospheres (RN) through treatment with metal‐phenolic coordination complexes results in the formation of a stable hybrid structure. This reconstructed structure enhances electron transfer efficiency, leading to improved photocatalytic performance. Due to the photoluminescence quenching property of RN and its electronic synergy with tannic acid (T) and zirconium (Z), the supramolecular complexes of hybrid nanospheres (RNTxZy) with Pt nanoparticles or a biological workhorse, Shewanella oneidensis MR‐1, showed marked improvement in photocatalytic hydrogen production. The supramolecular hybrid particles with a metal‐phenolic coordination layer showed 5.6‐ and 4.0‐fold increases, respectively, in the productivities of hydrogen evolution catalyzed by Pt (Pt/RNTxZy) and MR‐1 (M/RNTxZy), respectively. These results highlight the potential for further advancements in the structural and photochemical control of supramolecular nanomaterials for energy harvesting and bio‐hybrid systems. [ABSTRACT FROM AUTHOR]