Application In Organic Solar Cells Research Articles

Design of Isoindigo-Based Small-Molecule Donors for Bulk Heterojunction Organic Solar Cell Applications in Combination with Nonfullerene Acceptors.

The development of small-molecule organic solar cells with the required efficiency depends on the information obtained from molecular-level studies. In this context, 39 small-molecule donors featuring isoindigo as an acceptor moiety have been meticulously crafted for potential applications in bulk heterojunction organic solar cells. These molecules follow the D2-A-D1-A-D2 and D2-A-π-D1-π-A-D2 framework. Similar molecules considered in the previous experimental study (molecules R1 ((3E,3″E)-6,6″-(benzo[1,2-b:4,5-b']dithiophene-2,6-diyl)bis(1,1'-dimethyl-[3,3'-biindolinylidene]-2,2'-dione)) and R2 ((3E,3″E)-6,6″-(4,8-dimethoxybenzo[1,2-b:4,5-b']dithiophene-2,6-diyl)bis(1,1'-dimethyl-[3,3'-biindolinylidene]-2,2'-dione))) have been chosen as reference molecules. Molecules with and without π-spacers have been considered to understand the impact of the length of the π-spacer on intramolecular charge-transfer transitions and absorption properties. A detailed investigation is carried out to establish the relationship between the structure and photovoltaic parameters using density functional theory and time-dependent density functional theory methods. The newly developed molecules exhibit better electronic, excited-state, and charge transport properties than the reference molecules. Additionally, model donor-acceptor interfaces are constructed by integrating the designed donor molecules with fullerene/nonfullerene acceptors. The electronic and excited-state properties of these interfaces are rigorously evaluated. Results elucidate that the donor comprising of isoindigo-bithiophene-pyrroloindacenodithiophene (IIG-T2-PIDT) emerges as a promising candidate for bulk heterojunction solar cells based on nonfullerene acceptors. This research provides systematic design strategies for the development of small-molecule donors for organic solar cells.

Establishing Co‐Continuous Network of Conjugated Polymers and Elastomers for High‐Performance Polymer Solar Cells with Extreme Stretchability

AbstractHigh power conversion efficiency (PCE) and mechanical robustness are prerequisites for wearable applications of organic solar cells (OSCs). However, stretchability of present active systems (i.e., crack‐onset strain (COS) < 30%) should be improved. While introducing elastomers into active systems is considered a simple method for improving stretchability, the inclusion of elastomers typically results in a decrease in PCE of the OSC with a limited enhancement in the stretchability due to lack of interconnected electrical and mechanical pathways. In this study, it is developed efficient and intrinsically stretchable (IS)‐OSCs with exceptional mechanical robustness, by constructing co‐continuous networks of conjugated polymers (D18) and elastomers (SEBS) within active layers. It is demonstrated that the blend film with a specific ratio (40:60 w/w) of D18:SEBS is crucial for forming co‐continuous structures, establishing well‐connected mechanical and electrical channels. Consequently, D180.4:SEBS0.6/L8‐BO OSCs achieve 16‐times higher stretchability (COS = 126%) than the OSCs based on D18/L8‐BO (COS = 8%), while achieving 4‐times higher PCE (12.13%) compared to the OSCs based on SEBS‐rich active layers (D180.2:SEBS0.8/L8‐BO, PCE = 3.15%). Furthermore, D180.4:SEBS0.6‐based IS‐OSCs preserve 86 and 90% of original PCEs at 50% strain and after 200 stretching/releasing cycles with 15% strain, respectively, demonstrating the highest mechanical robustness among reported IS‐OSCs.

High Performance As-Cast Organic Solar Cells Enabled by a Refined Double-Fibril Network Morphology and Improved Dielectric Constant of Active Layer.

High performance organic solar cells (OSCs) are usually realized by using post-treatment and/or additive, which can induce the formation of metastable morphology, leading to unfavorable device stability. In terms of the industrial production, the development of high efficiency as-cast OSCs is crucially important, but it remains a great challenge to obtain appropriate active layer morphology and high power conversion efficiency (PCE). Here, efficient as-cast OSCs are constructed via introducing a new polymer acceptor PY-TPT with a high dielectric constant into the D18:L8-BO blend to form a double-fibril network morphology. Besides, the incorporation of PY-TPT enables an enhanced dielectric constant and lower exciton binding energy of active layer. Therefore, efficient exciton dissociation and charge transport are realized in D18:L8-BO:PY-TPT-based device, affording a record-high PCE of 18.60% and excellent photostability in absence of post-treatment. Moreover, green solvent-processed devices, thick-film (300nm) devices, and module (16.60 cm2) are fabricated, which show PCEs of 17.45%, 17.54%, and 13.84%, respectively. This work brings new insight into the construction of efficient as-cast devices, pushing forward the practical application of OSCs.

Designing simple non-fused terthiophene-based electron acceptors for efficient organic solar cells

Low-cost photovoltaic materials are essential for realizing large-scale commercial applications of organic solar cells (OSCs). However, highly efficient OSCs based on low-cost photovoltaic materials are scarce due to a deficiency in understanding the structure-property relationship. Herein, we investigated two low-cost terthiophene-based electron acceptors, namely, 3TC8 and 3TEH, with 3,4-bis(octan-3-yloxy)thiophene, differing only in the alkylated thiophene-bridges. Both acceptors exhibit low optical gaps (∼1.43 eV) and possess deep highest occupied molecular orbital (HOMO) levels (∼−5.8 eV). Notably, the single-crystal structure of 3TEH demonstrates highly planar conjugated backbone and strong π-π stacking between intermolecular terminal groups, attributed to the presence of the bulky alkylated noncovalently conformational locks. Upon utilizing both acceptors to fabricate OSCs, the 3TC8-based device exhibited a power conversion efficiency (PCE) of 11.1%, while the 3TEH-based OSC demonstrated an excellent PCE of 14.4%. This PCE is the highest among OSCs based on terthiophene-containing electron acceptors. These results offer a new strategy for designing low-cost electron acceptors for highly efficient OSCs.

Computational method on highly efficient D-π-A-π-D-based different molecular acceptors for organic solar cells applications and non-linear optical behaviour

Eight molecular structures (BT-A1 to BT-A8) with high-performance non-fullerene acceptor (NFA) were selected for organic solar cells (OSCs) and non-linear optical (NLO) applications. Their electronic, photovoltaic (PV) and optoelectronic properties were tuned by adding powerful electron-withdrawing groups to the acceptor (A) of the D-π-A-π-D structure. Using time-dependent density functional theory (TD-DFT) techniques, based on the laws of quantum chemical calculations, the absorption spectra, stability of the highest and lowest-energy molecular orbitals (HOMO/LUMOs), electron density, intramolecular charge transfer (ICT), transition density matrix (TDM), were examined. The binding energy (Eb) and density of states (DOS) were probed to realize the optoelectronic analysis of the structures BT-A1 to BT-A8. Noncovalent interactions (NCIs) based on a reduced density gradient (RDG) were used to describe the nature and strength of D-A interactions in the molecules BT-A1 to BT-A8. The new refined molecules BT-A1 to BT-A8 exhibited strong absorbance bands between 408–721 nm and high electron transfer contribution (ETC) ranges between 87–96 %, along with the smallest excitation energies (Ex) between 1.71–3.55 eV in the solvent dichloromethane. Dipolar moment strengths ranging from 0.38 to 4.72 Debye in both the excited and ground states have determined with good solubility properties of BT-A1 to BT-A8 in polar solvent. Highly effective charge mobilities and prevention of charge recombination have been demonstrated by the electron (0.18–0.41 eV) and hole RE values (0.13–0.89 eV) for the new compounds. Power conversion efficiencies (PCE) of BT-A1 to BT-A8 were nearly the same because of better outcomes compared to the molecules in the BT. Compared to poly[4.8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b: 4,5-b']dithiophene-2,6- diyl-alt-(4–2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2–6-diyl)] (PTB7-Th), the open circuit voltages (Voc) of compounds BT-A1 to BT-A8 were ranged from 1.52 to 2.13 eV. The polarizability (α) and hyperpolarizability (β) of the molecules BT-A1 to BT-A8 were used to determine the non-linear optical (NLO) properties. The results showed that BT-A2, BT-A6 and BT-A7 have good NLO activity. This computational analysis demonstrates the superiority of the molecules with NFA. Hence the compounds are advised for the use in production of high-performance OSCs and NLO activity.

Triflic Acid-Assisted Regioselective Bromination of Quinoxaline Derivatives Enables a Facile Synthesis of Polymer PTQ10.

Poly[(thiophene)-alt-(6,7-difluoro-2(2-hexyldecyloxy)quinoxaline)] (PTQ10) emerges as a promising candidate for donor materials in organic solar cells (OSCs) due to its high efficiency, simplified synthesis, and cost-effectiveness. The acceptor unit of PTQ10 is derived from the alkylation of 5,8-dibromo-6,7-difluoroquinoxaline-2-ol, emphasizing the importance of its economical synthesis for commercial viability. This study investigates triflic acid-assisted regioselective bromination of quinoxaline derivatives and proposes an alternative synthetic pathway for PTQ10. The developed route benefits from concise synthetic steps, a dependable procedure, and high overall yield. Starting with the condensation of 4,5-difluorobenzene-1,2-diamine with ethyl oxoacetate to yield 6,7-difluoroquinoxaline-2-ol, subsequent triflic acid-assisted regioselective bromination produces 5,8-dibromo-6,7-difluoroquinoxaline-2-ol in high yield. Alkylation under Mitsunobu reaction conditions yields 5,8-dibromo-6,7-difluoro-2-(2-hexyldecyloxy)quinoxaline, followed by polymerization with 2,5-distannylated thiophene under Stille reaction conditions to afford PTQ10. This research provides insights into efficient synthetic strategies for PTQ10, advancing its potential for commercial application in OSCs.

Critical role of the end-group acceptor in enhancing the efficiency of indacenodithiophene-benzothiadiazole-linked nonfullerene organic solar cells through morphology optimization

Solution-processed organic solar cells (OSCs) have great promise for next-generation solar energy conversion technologies. Innovative acceptors are constantly being designed to improve device efficiency. In this work, we designed and synthesized a series of A–π–D–π–A type non-fullerene acceptor (NFA) molecules, named IB-TOT, IB-TOM, IB-IOO, and IB-IOM for their applications in OSCs. All molecules showed high thermal stability, broad photoabsorption, and relatively lower highest occupied molecular orbital (HOMO) energy levels from −5.48 eV to −5.58 eV. The optimized OSCs based on these NFAs and PTB7-Th donor deliver power conversion efficiencies (PCEs) of 8.19%, 5.50%, 2.42%, and 3.10% for IB-TOT, IB-TOM, IB-IOO, and IB-IOM molecules, respectively. The higher PCE of IB-TOT-based OSCs is attributed to their excellent miscibility and superior interpenetrating network morphology compared to the other three compounds. These results demonstrate that using the 3-ethylrhodanine acceptor unit to construct the NFA molecule is a successful approach for outstanding achievement in OSCs.

Optically Enhanced Semitransparent Organic Solar Cells with Light Utilization Efficiency Surpassing 5.5%

AbstractConverting non‐visual light into photocurrent while maintaining high visual transparency is vital for semitransparent organic solar cells (ST‐OSCs) application, yet often challenging over insufficient invisible light‐harvesting. Herein, spectrally selective optical manipulation for ST‐OSCs with high visual light transparency and full‐spectral non‐visual light reflection is proposed by matching the optical admittance of ultrathin Ag films using ZnS and MgF2. The reflection of optically enhanced ST‐OSCs at the spectral region beyond the human eye's response spectrum is improved and the transmission in the visual region is simultaneously enhanced. By further integrating an anti‐reflective structure, the optimal structure boosts the average visible transmittance and power conversion efficiency of ST‐OSCs to 44.3% and 12.6%, respectively, yielding a record light utilization efficiency of 5.6%. Corresponding flexible ST‐OSCs with high mechanical stability implies that this work provides a facile and universal strategy for ST‐OSCs aiming at building integrated photovoltaics.

Improved efficiency of polymer solar cells using alcohol-soluble self-doped N-type polymers as cathode interface layer

Extensive research has been conducted on polymeric cathode interface substances, known for their self-doping features, for their application in organic solar cells (OSCs) to improve the ohmic interaction at the electrode with the active layer. In this paper, two novel polymers, PIIDN-F and PIIDN-FN, with self-doping effect, were successfully synthesized by combining isoindigo (IID), which contains an amino side chain, as an electrons-deficient group with fluorene, which contains different side chains. A thorough examination was conducted on the self-doping properties, electrical conductivity, work efficiency, and the angle of water contact between the two substances. Following this, PIIDN-F and PIIDN-FN were effectively utilized as cathode interface layers (CILs) within PTB7-Th:PC71BM OSCs. The PIIDN-F and PIIDN-FN achieve power conversion efficiencies (PCEs) of 8.97% and 9.04%, respectively. Findings indicate that the quantity of polar groups significantly influences the polymer's conductivity, adjustable work function, and the interaction at interfaces. These results show that by simply adjusting the number of polar groups, it is possible to provide efficient CILs for high-performance OSCs.

High-performance intrinsically stretchable organic solar cells based on flexible spacer incorporated dimerized small-molecule acceptors

High power conversion efficiency (PCE), long-term stability, and mechanical robustness are important requirements for the practical applications of organic solar cells (OSCs). Herein, we develop a series of flexible spacer (FS)-incorporated dimerized small-molecule acceptors (DSMAs; DYBT-C0, DYBT-C4, and DYBT-C8) and demonstrate high-performance OSCs with a high PCE of 18.6%, excellent mechanical robustness (crack-onset strain (COS) = 32%) and photostability (t80% lifetime = 1735 h under 1-sun illumination). The incorporation of aliphatic FS units with optimal length effectively reduces the backbone rigidity of the DSMAs and increases the fraction of intermixed domains in the blend films, while maintaining excellent electron transport properties. The DYBT-C4-based OSCs demonstrate higher PCE (18.6%) and stretchability (COS = 32%) compared to the OSCs based on the monomer acceptor (MYT; PCE = 15.9% and COS = 10%) and DSMA without FS units (DYBT-C0; PCE =17.2% and COS = 17%). In addition, due to the reduced diffusion coefficient and higher glass transition temperature of DYBT-C4, the DYBT-C4-based OSCs exhibit photostability significantly higher than that of the OSCs fabricated using MYT (t80% lifetime= 36 h). Consequently, DYBT-C4-based intrinsically stretchable (IS)-OSCs exhibit high device stretchability (strain at PCE80% = 36%) and PCE of 14.3%, demonstrating potential for wearable applications.

5‐Bromosalicylaldehyde: Theoretical, Experimental and Spectroscopic (FT‐IR, Raman, H1 and C13‐NMR, UV‐Vis) Studies and Their Photovoltaic Parameters

AbstractThis study aims to identify a 5‐bromosalicylaldehyde (5BSA) and assess its performance for application in organic solar cells. In the current work, the 5BSA was investigated using various techniques such as FT‐IR, Raman, NMR, and UV‐Vis spectroscopy to characterize the title molecule. The possible conformers of the 5BSA were studied using the MMFF methodology in Spartan software. The geometry optimization of modifications for each conformation was computed using the DFT approach for the B3LYP/6‐311++G(d,p) functional. The energy and dipole moment of most stable form were determined −1879057.42 kcal/mol and 1.455 Debye, respectively. The FT‐IR and Raman vibrational frequencies, the H1 and C13 NMR chemical shift values (in vacuum and in DMSO‐d6), the UV spectrum calculations (both in vacuum and in the solvent ethanol), the HOMO‐LUMO energy, and the map of MEP. Meanwhile, by considering the properties of organic photovoltaic cells, the open‐circuit voltage (VOC), hole reorganization energy (λh) and electron reorganization energy (λe), light‐harvesting efficiency (LHE), total reorganization energy (λtotal), the short‐circuit current density (Jsc), the driving force (ΔGinject), binding energy (Eb) were also computed for the title compound. In addition, transition density matrix (TDM) and density of states (DOS) analyses were conducted for the 5BSA molecule.

Synthesis and characterization of small molecular electrolyte as an interlayer and its application in organic solar cells

A small molecule electrolyte (SME) based on the iodide ion (FN-NDI-I) was synthesized for organic solar cells as interlayers based on fullerene and non-fullerene systems. The utilization of ITO/ZnO/SME enhances the PCE of the fullerene-based device, with an increase observed from 8.63% (pristine ZnO) to 9.06%. In the non-fullerene case, the PCE of the device based on pristine ITO/ZnO reaches 14.9%. However, due to leakage current, the performance of the device using the ITO/ZnO/SME interlayer decreases to 11.5%. When ITO/SME is employed, the device attains a PCE of 14.5%, which closely approximates the performance of the non-fullerene device based on ITO/ZnO.

Two Completely Non‐Fused Ring Acceptors Working in an Alloy‐Like Model for Efficient and Stable Organic Solar Cells

AbstractSimple chemical structure and simplified synthesis process of active layer materials are critical for advancing the practical application of organic solar cells. Herin, two completely non‐fused ring electron acceptors BTZT‐2Cl and BTZT‐4Cl are developed. BTZT‐4Cl exhibits an enhanced absorption band, increases electrostatic potential differences with D18, and improves crystallinity and molecular packing properties. Consequently, the binary device based on BTZT‐4Cl displays a markedly improved efficiency of 14.12%, compared to the BTZT‐2Cl‐based device, which only achieves a moderate efficiency of 11.25%. More importantly, an alloy‐like structure can be formed by incorporating a small amount of high miscibility and compatibility BTZT‐2Cl. The ternary blend exhibits more compact molecular packing, efficient exciton dissociation, and an extended charge carrier lifetime due to the formation of an alloy‐like structure. The ternary device achieves a decent efficiency of 15.41% with superior thermal stability and a high T80 lifetime over 1600 h after being aged at 65 °C. These results establish it as the most efficient among devices based on completely non‐fused ring acceptors with both high efficiency and voltage. This study demonstrates a simple material design strategy and high‐performance device optimization techniques, which are critical for advancing practical applications in the OSC field.

Computational Prediction of an Antimony-Based n-Type Transparent Conducting Oxide: F-Doped Sb2O5.

Transparent conducting oxides (TCOs) possess a unique combination of optical transparency and electrical conductivity, making them indispensable in optoelectronic applications. However, their heavy dependence on a small number of established materials limits the range of devices that they can support. The discovery and development of additional wide bandgap oxides that can be doped to exhibit metallic-like conductivity are therefore necessary. In this work, we use hybrid density functional theory to identify a binary Sb(V) system, Sb2O5, as a promising TCO with high conductivity and transparency when doped with fluorine. We conducted a full point defect analysis, finding F-doped Sb2O5 to exhibit degenerate n-type transparent conducting behavior. The inherently large electron affinity found in antimony oxides also widens their application in organic solar cells. Following our previous work on zinc antimonate, this work provides additional support for designing Sb(V)-based oxides as cost-effective TCOs for a broader range of applications.

Predicting high performance optoelectronic attributes containing iso-indacenodithiophene-based photovoltaic materials for future solar cell technology

Enhancing photovoltaic materials with improved power conversion efficiency (PCE), conduction band, and electrochemical attributes for organic solar cell (OSC) applications is a forefront area of research. This study is centered on the simulating and computational characterization of iso-indacenodithiophen (iso-IDTIC)-based new molecules (AF01-AF10) to obtain optimal candidates for high-performance OSCs. The proposed molecules have excellent PCE (∼15.97 %), fill factor (54.67), and open-circuit voltage Voc = 1.41 V, better than previous reports. DFT simulations-based analysis, including TDM, FMO, MEP, DOS, Voc, reorganization energies of hole and electron, and charge transfer analysis, were employed to confirm and comprehend the photovoltaic properties of proposed molecules. Reduction in energy gap (2.30–2.50 eV), binding energy (0.28–0.29 eV), enhanced λmax (586–686 nm) with HOMO → LUMO (>96 %) charge transfer was examined as compared to R(2.54 eV, 608 nm). Moreover, higher excitation dissociation rate, TDM, HOMODonor-LUMOAcceptor blend study, and reorganizational energy for electron and hole results confirmed that proposed molecules are efficient photovoltaic candidates for future solar energy applications.

Research Advances of Nonfused Ring Acceptors for Organic Solar Cells.

The last few decades have witnessed the rapid development of organic solar cells (OSCs). High power conversion efficiencies (PCEs) of over 19% have been successfully achieved due to the emergence of fused-ring acceptors (FRAs). However, the high complexity and low yield for the material synthesis result in high production costs of FRAs, limiting the further commercial application of OSCs. In contrast, nonfused ring acceptors (NFRAs) with the merits of facile synthesis, high yield, and preferable stability can promote the development of low-cost OSCs. Currently, the PCEs of NFRAs-based OSCs have exceeded 17%, which is expected to reach efficiency comparable to that of the FRAs-based OSCs. This review describes the advantages of the recent advances in NFRAs, which emphasizes exploring how the chemical structures of NFRAs influence molecular conformation, aggregation, and packing modes. In addition, the further development of NFRA materials is prospected from molecular design, morphological control, and stability perspectives.

Effect of Sn nanoparticles on the optical properties of PEDOT:PSS thin films

Introduction: In this study, we focus on enhancing the optical properties of PEDOT:PSS thin films by incorporating pure Sn nanoparticles (NPs) synthesized using the ultrasonic ablation technique. The objective is to investigate the impact of Sn concentration on the optical characteristics of the films, with a specific emphasis on applications in organic solar cells.Methods: We systematically varied the concentrations of Sn in PEDOT:PSS thin films and characterized their optical properties. The index of refraction (n) and extinction coefficient (k) were precisely determined by analyzing the transmission and reflection spectra of the films. Additionally, Sellmeier’s dispersal model was employed to elucidate the obtained results of n, and dispersive factors were calculated and interpreted.Results: The incorporation of Sn nanoparticles led to improvements in the energy bandgap (Eg) values of PEDOT:PSS films. Notably, as the concentration of Sn increased, the n values decreased, indicating enhanced suitability for organic solar cell applications. The study also unveiled a decrease in the dielectric constant of PEDOT:PSS/Sn films with increasing Sn content, resulting in improved transmittance velocity and enhanced efficacy of microelectronic devices. This, in turn, promotes the development of large-frequency and large-velocity stretchy circuit boards.Discussion: The comprehensive assessment of optical and dielectric parameters, including complex dielectric constant, complex optical conductance, and nonlinear optical constants, provides valuable insights into the potential applications of PEDOT:PSS/Sn films. The larger nonlinear optical constants observed in the present films suggest their suitability for diverse applications such as all-optical switching, limiting, phase modulation, and frequency conversion. Overall, our findings highlight the promising potential of Sn-incorporated PEDOT:PSS thin films in advancing the field of optoelectronics and microelectronics.

Research progress and application of high efficiency organic solar cells based on benzodithiophene donor materials

AbstractIn recent decades, the demand for clean and renewable energy has grown increasingly urgent due to the irreversible alteration of the global climate change. As a result, organic solar cells (OSCs) have emerged as a promising alternative to address this issue. In this review, we summarize the recent progress in the molecular design strategies of benzodithiophene (BDT)‐based polymer and small molecule donor materials since their birth, focusing on the development of main‐chain engineering, side‐chain engineering and other unique molecular design paths. Up to now, the state‐of‐the‐art power conversion efficiency (PCE) of binary OSCs prepared by BDT‐based donor materials has approached 20%. This work discusses the potential relationship between the molecular changes of donor materials and photoelectric performance in corresponding OSC devices in detail, thereby presenting a rational molecular design guidance for stable and efficient donor materials in future.

Self-Assembled Monolayers for Interfacial Engineering in Solution-Processed Thin-Film Electronic Devices: Design, Fabrication, and Applications.

Interfacial engineering has long been a vital means of improving thin-film device performance, especially for organic electronics, perovskites, and hybrid devices. It greatly facilitates the fabrication and performance of solution-processed thin-film devices, including organic field effect transistors (OFETs), organic solar cells (OSCs), perovskite solar cells (PVSCs), and organic light-emitting diodes (OLEDs). However, due to the limitation of traditional interfacial materials, further progress of these thin-film devices is hampered particularly in terms of stability, flexibility, and sensitivity. The deadlock has gradually been broken through the development of self-assembled monolayers (SAMs), which possess distinct benefits in transparency, diversity, stability, sensitivity, selectivity, and surface passivation ability. In this review, we first showed the evolution of SAMs, elucidating their working mechanisms and structure-property relationships by assessing a wide range of SAM materials reported to date. A comprehensive comparison of various SAM growth, fabrication, and characterization methods was presented to help readers interested in applying SAM to their works. Moreover, the recent progress of the SAM design and applications in mainstream thin-film electronic devices, including OFETs, OSCs, PVSCs and OLEDs, was summarized. Finally, an outlook and prospects section summarizes the major challenges for the further development of SAMs used in thin-film devices.

Recent Advances in Selenium‐Containing Non‐fullerene Acceptors for High‐Performance Organic Solar Cells

AbstractThe diversity in molecular structures and solution processability of non‐fullerene acceptors (NFAs), particularly those containing selenium (Se), plays a pivotal role in advancing organic solar cells (OSCs). Among various molecular design strategies, the introduction of selenium atoms, characterized by their large covalent radius, loose electron cloud, and strong polarization properties, can enhance intermolecular Se‐Se interactions and improve the electron‐donating capability of π‐cores. This approach is considered a significant avenue for optimizing the photovoltaic performance of active layer materials. In this review, we provide a comprehensive summary of recent advancements in selenium‐containing acceptor molecules. These include ITIC‐based fused ring NFAs, Y6‐based fused ring NFAs, Y6‐based polymer acceptors, non‐fused ring electron acceptors and their application in tandem and ternary OSCs. Additionally, we analyze the future prospects and development of selenium‐containing NFAs with the goal of achieving OSC efficiencies exceeding 20 %.