Molecular photoswitches that absorb sunlight and store it in the form of chemical energy are attractive for applications in molecular solar thermal energy storage (MOST) systems. Typically, these systems utilize the absorbed energy to photoisomerize into a metastable form, which acts as an energy reservoir. Diarylethenes featuring aromatic ethene ?-linkers have garnered research interest in recent years as a promising class of T-type photoswitches, which undergo photocyclization from an aromatic ring-open form into a less aromatic or non-aromatic ring-closed form. Based on several recent computational and experimental studies, this perspective analyzes the potential of these switches for MOST applications. Specifically, we discuss how they can be made to simultaneously achieve high energy-storage densities, long energy-storage times, and high photocyclization quantum yields by tuning the aromatic character of the ethene ?-linker

Organic solar cells (OSCs) have achieved remarkable progress, with power conversion efficiencies (PCEs) surpassing 19–20%, driven by the development of polymeric electron donors and non-fullerene acceptors (NFAs) in bulk-heterojunction (BHJ) architectures. BHJ OSCs, which rely on physical blending of donor (D) and acceptor (A) materials, face significant challenges in maintaining long-term stability. This instability limits the commercial viability of BHJ OSCs despite advancements in optimizing their morphology and device architecture. Single-component organic solar cells (SCOSCs) have emerged as a promising alternative to address these stability challenges. By covalently linking D and A units into a single molecule these single-material devices combine the advantages of light absorption and charge transport within a unified structure, eliminating complex interfacial layers and mitigating phase-separation issues inherent in BHJ systems. To date, SCOSCs have reached a maximum power conversion efficiency (PCE) of 15%, marking notable progress toward bridging the performance gap with BHJ devices. This review highlights the structural advancements in SCOSCs, with a particular emphasis on molecular dyads, D–A double cable polymers and conjugated block copolymers, and their photovoltaic performance. Furthermore, it discusses potential strategies for future innovations to improve the efficiency and scalability of SCOSCs.

Metal doping offers a potent strategy for enhancing the optical properties and stability of CsPbCl3 (CPC) perovskites. While Mn doping has drawn attention to its unique attributes, it has failed to achieve the benchmarks set by CsPbBr3 and CsPbI3. To bridge this gap, a codoping approach involving earth-abundant and cost-effective FeCl2 has been explored in this study. PL emission peak intensity increased after codoping with various FeCl2 concentrations in Mn-doped CPC (Mn-CPC) nanocrystals. Fe2+ effectively enhances the Mn doping efficiency in CPC across 0.1–0.3 mmol concentrations by replacing some Pb2+ sites. The resultant Fe-codoped Mn-CPC nanocrystals display orange emission in hexane at 594–606 nm, boasting photoluminescence quantum yields up to 22–27%. Notably, codoped nanocrystals exhibit better photostability under ambient conditions and UV-light irradiation than Mn-CPC. The improved photoresponse characteristics induced by Fe2+ codoping highlight the potential of these nanocrystals for integration into UV–visible photodetectors and other optoelectronic devices. The electrochemical property of Fe ion-codoped Mn-CPC PNCs showed better photocurrent density results than Mn-CPC

Utilizing hole-transporting materials (HTMs) to extract and transport holes from perovskite materials to the electrode remains essential in most perovskite solar cell (PSC) architectures. Developing cost-effective and efficient HTMs is essential for advancing PSC technology. We have synthesized a novel HTM, TPA-IDT-TPA, which has an extended fused ring as the core moiety called indacenodithiophene (IDT) and p-methoxy triphenylamine (p-mTPA) as terminal groups. TPA-IDT-TPA exhibits appropriate frontier molecular orbital (FMO) energy levels that match perovskite materials. Density functional theory (DFT) simulations were performed to comprehend the electronic, excited-state, and charge transport properties. The DFT results indicate that the extended ?-conjugation, rigidity, and the central core ring of the HTM enhanced the ?-? stacking, contributing to efficient charge transport. The PSC constructed with TPA-IDT-TPA achieves a device efficiency of 8.34%, with high values of JSC and VOC, which can be further enhanced through molecular optimization. © 2024 International Solar Energy Society

In order to attain high performance in single-component organic solar cells (SCOSCs), it requires the designing of light-harvesting structures that can absorb light across a wide range from visible to near-infrared (NIR) wavelengths. In this investigation, two novel dyad materials, denoted as SPS-BF-Full and SPS-BT-Full are designed and synthesized, consisting of covalently linked benzofuran (BF) and benzothiophene (BT) functionalized thiophene–diketopyrrolopyrrole (TDPP) as donor and N-methyl fullero[60]pyrrolidine as the acceptor, respectively. The incorporation of a phenyl bridge between TDPP and fullero[60]pyrrolidine enhances light absorption in SPS-BF-Full and SPS-BT-Full, resulting to a high short-circuit density (JSC). Consequently, the SCOSCs utilizing SPS-BT-Full and SPS-BF-Full attained overall power conversion efficiency (PCE) of 6.28 and 7.35%, respectively. The high photovoltaic performance of OSCs utilizing SPS-BF-Full is mainly attributed to its higher external quantum efficiency and balanced hole and electron mobility (?e/?h=1.39), along with imporved charge carrier extraction, revealing more effective charge transport in comparison to SPS-BT-Full counterparts

Type II heterostructures formed by organic semiconducting ligands and inorganic layers in two-dimensional (2D) hybrid perovskites can offer separated charge transport channels for holes and electrons. In this work, we studied a new lead-based 2D Dion-Jacobson perovskite structure incorporating simple terphenyl diammonium salts as organic spacers. The investigations of the electronic and photophysical properties, combined with theoretical calculations, indicate that this 2D perovskite structure forms a type II heterostructure producing intercalated separate pathways for electrons and holes that can migrate within the inorganic and organic sublayers, respectively. The charge transport properties of this unusual type II 2D perovskite heterostructure have also been successfully investigated for the first time by the space charge limited current (SCLC) method, and maximum electron and hole mobilities based on single-crystal devices were evaluated to be 0.3 cm V s and 7.0 × 10 cm V s, respectively. This work gives valuable insights into the charge transport mechanisms of type II heterostructures and paves the way toward optoelectronic device applications for such Dion-Jacobson-type 2D perovskites.