Application In Organic Solar Cells Research Articles

Tuning the optoelectronic properties of ZOPTAN core-based derivatives by varying acceptors to increase efficiency of organic solar cell.

In this theoretical study, quantum chemical analysis of five novel non-fullerene donor molecules designed from recently reported highly efficient (11.5%) donor molecule P2TBR, containing non-fused ring central thiophene-benzene-thiophene core, 2-D benzodithiophene donors, and end capped 3-methylrhodanine acceptors, has been performed to evaluate the photovoltaic parameters and their application in organic solar cells. These donor molecules consist of centrally introduced acrylonitrile acceptors in between thiophene-benzene-thiophene core of P2TBR, namely M1. Compounds M2-M5 were designed from M1 containing ZOPTAN core, through peripheral acceptor group modification by 2-methylenemalononitrile (M2), methyl 2-cyanoacrylate (M3), 2-(5,6-difluoro-2-methylene-3-oxo-2,3-dihydroinden-1-ylidene) malononitrile (M4), and 2-(3-methyl-5-methylene-4-oxothiazolidin-2-ylidene) malononitrile (M5). DFT and TD-DFT simulations of all molecules including reference were carried out using MPW1PW91 functional in conjunction with 6-31G (d, p) basis set. Optoelectronic properties, exciton dynamics, electron density distribution pattern, and charge mobility were further analyzed by absorption spectra, TDM plots, frontier molecular orbitals (FMO) analysis, and calculation of reorganization energies, respectively. Results reveal that central addition and end capped modification of acceptors in designed molecules proved to be effective strategy to finely tune the electronic and optical characteristics. Amongst all designed molecules, M4 exhibited improved opto-electronic parameters such as highest maximum absorption (695nm) in chloroform, least band gap (2.24eV), lowest values of λh (0.0034eV), and λe (0.0054eV) and lowermost binding energy (0.46eV), because of mutual effect of extended pi-conjugation and significant electron pulling nature of terminal acceptors. Moreover, higher dipole moment, lower values of hole reorganization energy, and improved Voc of designed molecules than reference (R) make them efficient donors to enhance PCE of photovoltaic materials.

Impact of π-linker modifications on the photovoltaic performance of rainbow-shaped acceptor molecules for high performance organic solar cell applications

Non-fullerene acceptor (NFA) materials attracted a huge attention because of their tendency to improve the power conversion efficiency (PCE) of organic solar cells (OSCs). Herein, we intended to demonstrate the efficient designing of a series of Rain-bow shaped materials (LB1 to LB5). These acceptor materials are designed by various end-capped modifications in a synthetically reported π-linker CH1007 molecule (reference R). The photovoltaic, optoelectronic, structural-property relationship, and physiochemical properties are specifically realized by using density functional theory (DFT) and time-dependent (TD-DFT) at B3LYP/6-31G (d,p). Our designed materials (LB1 to LB5) significantly occupied a narrower energy bandgap (Eg) (Eg = 1.87–2.01 eV) in-contrast to R and found highly red-shifted in absorption spectrum with lower excitation energies. The reorganization energy studies showed that the newly designed materials (LB1 to LB5) exhibited a better electronic mobility (λh = 0.0153 to 0.0190) as compared with R (λh = 0.0194). The higher open circuit voltage (Voc), and lower binding energy (Eb) values suggested that these designed materials (LB1 to LB5) are best fitted to prepare highly efficient OSCs devices. To study the charge transfer behavior, a donor:acceptor (D:A) blend study has also been performed to estimate an efficient charge transport phenomenon at the D:A interface. The outcomes of all analysis suggested that this designed series (LB1 to LB5) could be effective for the future development of highly efficient OSCs devices.

Synthesis of selenophene substituted benzodithiophene and fluorinated benzothiadiazole based conjugated polymers for organic solar cell applications

A series of alternating conjugated copolymers which contain selenophene modified benzodithiophene and fluorine bearing benzothiadiazole have been synthesized via Stille polycondensation reaction to investigate the effect of the number of fluorine atoms substituted to the benzothiadiazole. Three different polymers, PBDTSe-BT, PBDTSe-FBT and PBDTSe-FFBT, were reported and their electrochemical, spectroelectrochemical, and photovoltaic behaviors were examined. Density functional theory calculations were performed on model tetramer structures to shed light on how substituting the fluorine atom to the acceptor building block affects the structural, electronic and optical properties of the polymers. The results of computational studies were compared with experimental studies. The structure adjustment accomplished by fluorine substitution on the benzothiadiazole moiety reveals an influence on the electronic structure of polymers with a more negative HOMO energy level. A high VOC for the resulting photovoltaic device was examined for PBDTSe-FFBT. Difluorinated polymer PBDTSe-FFBT:PC71BM organic solar cell exhibited the highest photovoltaic performance of 2.63% with JSC of 7.24 mA cm-2, VOC of 0.72 V and FF of 50.6%. PBDTSe-BT:PC71BM revealed the best PCE as 2.39%, and the device reached the highest efficiency up to 1.68% for PBDTSe-FBT:PC71BM.

Deciphering the role of end-capped acceptor units for amplifying the photovoltaic properties of donor materials for high-performance organic solar cell applications

Non-fullerene organic solar cells (OSCs) deliver the highest efficiency gains overall in reported literature. Efforts are being made to refine efficacies and stabilities of organic solar cells through the designing of acceptor molecules that contain powerful electron-withdrawing groups. Here, we computed four acceptors (Y1-Y4) by end-capped alterations on reference R and optimize photophysical, optoelectronic and photovoltaic properties. Therefore, certain properties such as orientation of FMO’s, excitation and binding energy, open-circuit voltage (Voc), transition density matrix and reorganizational energy of hole and electron are observed in comparison with reference. The calculated molecular structures of Y1 and Y4 show a high red-shift, while that of Y2 and Y3 display slightly blue-shift, along with very fine excitation energies and high charge mobilities. All these molecules (Y1-Y4) and the reference R presents band-gaps as small as 1.5–2.5 eV, and considerable charge transfer potential. This theoretical system shows that end-capped acceptors alteration is quite remarkable to establish desired optoelectronic properties. Thus, Y1-Y4 are suggested to researchers aiming at the potential commercialization of highly efficient solar cells systems.

Low‐cost and efficient organic solar cells based on polythiophene‐ and poly(thiophene vinylene)‐related donors

AbstractAt present, most of state‐of‐the‐art power conversion efficiencies (PCEs) of organic solar cells (OSCs) are achieved from the photoactive materials involving donor–acceptor (D–A) copolymer donors. It is well known that the complicated molecular structure of D–A copolymers means the tedious synthesis, which brings about severe cost issue and poor scalability for the industrial production. Therefore, to develop application‐oriented OSCs, considerable attention should be paid on simplifying the chemical structures of polymer donors. Polythiophene (PT) and poly(thiophene vinylene) (PTV) derivatives should be among the simplest polymer donors, and OSCs based on them have made some breakthroughs in past 2 years. Here, we briefly introduce the recent advances of OSCs based on low‐cost polymers including poly(3‐hexylthiophene) (P3HT), PT derivatives, and PTV derivatives, respectively, and emphasize the importance of modulating energy levels, preaggregation effect, and D/A miscibility for the past progress as well as the future development. At last, we also propose some challenges demanding prompt solution for realizing practical application of OSCs, aiming at providing guidance and stimulating new ideas for further research.

DFT/TDDFT Investigation on donor-acceptor triazole-based copolymers for organic photovoltaics

Using density functional theory (DFT) method, we studied several triazole-based donor-acceptor (DA) π-conjugated molecules and evaluated their lowest unoccupied molecular orbital (LUMO) energies. Our results shows that bithiophene-substituted triazole-based acceptors with short and non-bulky substituents tend to be co-planar and hence exhibit stronger conjugation and electron delocalization, thereby leading to lower orbital energies of LUMO. Introduction of heteroatom such as S and Se within the chemical structure of triazole-based acceptor also significantly reduces the bandgap by lowering the LUMO energies. Among the donor fragments studied, a dithieno [3,2-b:2′,3′-d]phosphole donor fragment (Y4) led to donor-acceptor (DA) pairs with comparatively lower highest occupied molecular orbitals (HOMO, (-5.01 to -4.69 eV) along with higher VOC (>1.29 eV) without much compromise in its bandgap energy. This makes such DA-based polymers promising for bulk heterojunction solar cell applications. TD-DFT calculations were further used to simulate the absorption spectra of the DA monomers and showed that most pairs gave meaningful absorption from 400 to 1100 nm. More interestingly, the addition of long aromatic substituents in the acceptor fragment tends to give broader absorption spectra. Further studies on trimers with DDA repeating unit revealed that copolymers bearing Y4 and a benzo [1,2-d;4,5-d’]bitriazole X1 (or X6) exhibits close to ideal band gap of 1.37 eV (1.36 eV) with favorable open circuit voltage 1.23 eV, though absorption by Y4-Y4-X1 takes place in Infrared scope with higher oscillator strength. All in all, we identified a polymer comprising Y4 donor and X1 acceptor fragment to be a promising material for heterojunction organic solar cell application.

Photophysical Properties of the PVK-MEH-PPV/PCBM Composite for Organic Solar Cells Application: Synthesis, Characterization and Computational Study.

The physical and chemical properties of a new organic composite including PVK-MEH-PPV bi-block copolymer and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) were recorded. The functionalization and the charge transfer that occurs between donor and acceptor were examined and computed. In fact, the stationary and time-resolved photoluminescence properties were used to examine the effect of the PCBM on the optical properties of the PVK-MEH-PPV matrix. The photoluminescence quenching accompanied by faster PL decay confirmed the charge transfer and interaction process. The electrical and optoelectronic properties and the charge carriers’ injection in the resulting composite were examined. The experimental conclusion was corroborated and confirmed by a calculation based on density functional theory (DFT). Hence, the combination of experimental and theoretical results indicated that the result composite can be applied as an active layer for organic solar cells.

Efficient organic solar cells with superior stability based on PM6:BTP-eC9 blend and AZO/Al cathode

SummaryAlthough efficiency over 18% has been achieved, the real application of organic solar cells is still impeded by inferior stability because of degradation and limited studies. Here we report efficient normal structure organic solar cells delivering promising stability under different conditions, based on PM6:BTP-eC9 blend and AZO/Al cathode. The impact of cathode on device stability is systematically studied by screening the leading electron transporting layers i.e., AZO, PFN-Br, PDINN, and metal electrodes (Al and Ag). Strong correlation between cathode and stability is demonstrated. The optimal AZO/Al-cathode device delivers the best efficiency of 15.76%, with shelf-stability of T83 > 1,200 h, thermal stability of T60 > 300 h, and MPP operational stability of T87 > 500 h. As far as we know, this is the best stability achieved for PM6:Y6/derivative cells in literature so far, based on well-studied simple cathode system and without any tailoring/dopant for the active blend.

Ti-Oxo Clusters with Peripheral Alkyl Groups as Cathode Interlayers for Efficient Organic Solar Cells.

Three independent Ti-oxo clusters (TOCs) that contain 6, 8, and 12 Ti atoms in the cores and alkyl groups on the surface were developed as cathode interlayers in bulk-heterojunction organic solar cells (OSCs). These TOCs have precise chemical structures with a single crystal, excellent solubility in methanol, and well-aligned work function. Smooth films can be facilely obtained by spin-casting their solution on top of the active layer. Therefore, they can be used as an interlayer in OSCs to provide a high power conversion efficiency (17.29%). Further studies reveal that these TOCs can not only reduce the work function of the silver electrode to provide better energy level alignment but also exhibit a significant n-doping effect with the non-fullerene acceptors to facilitate efficient electron extraction and transport. Our results demonstrate that TOCs as semiconductors have great potential application in OSCs.

Effect of Thermal Annealing on the Charge Carrier Selectivity of Ultra‐Thin Organic Interface Dipoles in Silicon Organic Heterojunction Solar Cells

Interfacial layers consisting of organic molecules with a permanent dipole moment exhibit enhanced charge carrier selectivity when applied as electron‐selective contacts in crystalline silicon (c‐Si) heterojunction solar cells. It is found that thermal annealing has a detrimental effect on the charge carrier selectivity of dipole materials based on the amino acid l‐histidine mixed with a fluorosurfactant. Although, the implied open‐circuit voltage (iVoc) increases with annealing, the Voc decreases significantly which is accompanied by a decrease in the built‐in voltage (Vbi) and increase in the specific contact resistivity (ρc). Based on numerical device simulations, it is concluded that the tunneling of electrons through the dipole layer becomes less effective with increasing annealing temperature due to the decomposition of the dipole materials. The decomposition leads to a more “resistive” interfacial layer and to a gradient in the electron quasi‐Fermi potential and, thus, a decrease in Voc. Furthermore, storage under ambient air at room temperature degraded the electron‐selective contacts substantially, limiting the potential of the dipole material for the application in silicon organic heterojunction solar cells.

Thickness-Insensitive Anode Interface Layer for High-Efficiency Organic Solar Cells.

Thickness-insensitive anode interface layer materials are extremely crucial for commercial applications of organic solar cells (OSCs). Here, we have demonstrated a solution-processed and thickness-insensitive anode interfacial layer PCPDT-2Ph-H and employed it in large-area OSCs. The power conversion efficiency (PCE) of a PM6:Y6 device with a 0.04 cm2 area using PCPDT-2Ph-H as the anode interface layer can reach 16.5%. More importantly, when the thickness of PCPDT-2Ph-H reaches 100 nm, a device with a 1.0 cm2 effective area can still achieve a high efficiency of 10.3%, which is highly favorable to large-area printing of OSCs. Due to its advantages of thickness insensitivity and solution processing, PCPDT-2Ph-H would be a promising anode interface layer for large-area OSCs.

Theoretical study of dipyridine phenanthrene derivatives for BHJ organic solar cells application: a DFT approach

Theoretical study of dipyridine phenanthrene derivatives for BHJ organic solar cells application: a DFT approach

Deciphering the role of invited guest bridges in non-fullerene acceptor materials for high performance organic solar cells

Fullerene-free acceptor molecules gained great attention of researchers due to their excellent light harvesting capability and low toxicity rate. Herein, six new molecules have been designed by bridging core modifications and analyzed through advanced quantum chemical techniques. Density functional theory and time dependent-DFT have been employed in order to compute optoelectronic, photovoltaic and physiochemical properties of newly designed molecules. Some geometric parameters like alignment of both molecular orbitals, absorption maxima, excitation with binding energies, open circuit voltage, and transition density matrix have been performed in order to examine the structural-property relationship of designed molecules. Efficient bridge atoms of designed molecules cause reduction in energy band gap (1.895–2.375 eV) along with red-shifting in absorption maxima (619–719 nm). Transition density matrix analysis unveils the location of charge density within a molecule along with different transitions. Molecular electrostatic potential analysis suggested that the theoretical planned molecules are symmetrical and have electron rich and poor regions. High open circuit voltage and electron-hole mobility advocated that the designed molecules are good nominees for high performance organic solar cell applications.

Explore fused-ring core incorporated A-π-D-π-A type acceptors and their application in organic solar cells: Insight into molecular conformation, optical and electrochemical properties, film morphology, and energy loss

Acceptor-π-Donor-π-Acceptor (A-π-D-π-A) type fused-ring electron acceptors (FREAs) are a class of important nonfullerene acceptors for fabricating high efficiency organic solar cells (OSCs). However, limited by the rare types of the central D core, the efficiencies of the OSCs based on A-π-D-π-A FREAs are falling behind. In this work, dithienopyrrolobenzothiadiazole (DTPBT) was employed in developing A-π-D-π-A type FREAs, and was assessed as a D core. DTPBT based FREAs were synthesized and compared with the typical A-π-D-π-A type FREAs using IDT as the D core, from aspects of molecular conformation, optical and electrochemical properties, blend film morphology, and energy loss. Compared to traditional IDT based A-π-D-π-A type FREAs (IRIC-4F), A-π-D-π-A FREAs containing DTPBT (BTOT-OD-4F) showed C-type molecular conformation, redshifted absorption and downshifted energy levels. As a result, the corresponding devices achieved an efficiency of over 13% with improved JSC of 23.44 mA cm−2 and a fair FF of 66.9%. Meanwhile, the energy loss of the PBDB-T: BTOT-OD-4F blends reduced effectively, due to the contribution of suppressed nonradiative recombination. Above all, DTPBT has presented its potential in developing highly efficient A-π-D-π-A type FREAs. To realize the best performance of the novel acceptors, further systematic and synergetic optimization of the molecule structure and device fabrication are needed. This work has demonstrated a new design manner of A-π-D-π-A type FREAs through exploring novel fused-ring cores, which facilitates reduced energy loss of the corresponding devices.

Semitransparent organic solar cells based on all-low-bandgap donor and acceptor materials and their performance potential

Recent advances in organic solar cells (OSCs) based on large-bandgap donors and low-bandgap non-fullerene acceptors (NFAs) have increased the power conversion efficiency (PCE) of OSCs to ~18%. However, these state-of-the-art OSCs have strong absorption in the visible region, limiting their application in semitransparent organic solar cells (STOSCs). In this study, an all-low-bandgap system based on a low-bandgap polymer donor (PM2) and a low-bandgap NFA (Y6-BO), was introduced as the light-harvesting layer for STOCSs with absorption mainly localized in the near-infrared (NIR) spectrum from 600 to 900 nm. The corresponding opaque OSCs exhibited the highest PCE among reported all-low-bandgap OSC systems, and the corresponding STOSCs showed higher visible light transmittances (VLTs) and light utilization efficiencies (LUEs) than the reference devices based on state-of-the-art PM6:Y6-BO OSC system with broad range absorption from visible to NIR. Optical simulations predicted that the PM2:Y6-BO-based STOSCs have a greater potential to realize higher VLTs and PCEs and better PCE retention (PCEsemitransparent/PCEopaque) than those from the PM6:Y6-BO-based STOSCs. Guided by these simulations, PM2-based STOSCs with VLTs exceeding 40% and PCEs of ~6% were achieved. Further recombination analysis suggested that the PM2-based devices experienced more severe charge recombination and energy losses, indicating there is further room for PCE improvement by designing new all-low-bandgap systems. Overall, this work shows the great potential of all-low-bandgap systems in realizing STOSCs with high PCEs and VLTs, which is promising for the commercialization of OSCs as power-generating window applications.

Recent Advances of Chlorination in Organic Solar Cells

AbstractChlorination has been used in the fields of organic solar cells (OSCs) for a long time, and impressive progress has been made over the years. Recently developed chlorinated OSCs have achieved an efficiency of over 18%. For better understanding and application of chlorination in the fields of OSCs, we will briefly introduce the general properties of chlorine and recent advances in its introduction and applications in OSCs in this cluster article. Finally, we also provide a short discussion of current questions regarding chlorination in OSCs and future developments in this area.

Utilizing 3,4-ethylenedioxythiophene (EDOT)-bridged non-fullerene acceptors for efficient organic solar cells

A rational design of efficient low-band-gap non-fullerene acceptors (NFAs) for high-performance organic solar cells (OSCs) remains challenging; the main constraint being the decrease in the energy level of the lowest unoccupied molecular orbitals (LUMOs) as the bandgap of A-D-A-type NFAs decrease. Therefore, the short current density (Jsc) and open-circuit voltage (Voc) result in a trade-off relationship, making it difficult to obtain efficient OSCs. Herein, three NFAs (IFL-ED-4F, IDT-ED-4F, and IDTT-ED-2F) were synthesized to address the above-mentioned issue by introducing 3,4-ethylenedioxythiophene (EDOT) as a π-bridge. These NFAs exhibit relatively low bandgaps (1.67, 1.42, and 1.49 eV, respectively) and upshifted LUMO levels (-3.88, −3.84, and −3.81 eV, respectively) compared with most reported low-band-gap NFAs. Consequently, the photovoltaic devices based on IDT-ED-4F blended with a PBDB-T donor polymer showed the best power conversion efficiency (PCE) of 10.4% with a high Jsc of 22.1 mA cm−2 and Voc of 0.884 V among the examined NFAs. In contrast, IDTT-ED-4F, which was designed with an asymmetric structure of the D-π-A type, showed the lowest efficiency of 1.5% owing to the poor morphology and charge transport properties of the binary blend. However, when this was introduced as the third component of the PM6:BTP-BO-4Cl, complementary absorption and cascade energy-level alignment between the two substances could be achieved. Surprisingly, the IDTT-ED-4F-based ternary blend device not only improved the Jsc and Voc, but also achieved a PCE of 15.2%, which is approximately 5.3% higher than that of the reference device with a minimized energy loss of 0.488 eV. In addition, the universality of IDTT-ED-2F as a third component was effectively demonstrated in other photoactive systems, specifically, PM6:BTP-eC9 and PTB7-Th:IEICO-4F. This work facilitates a better understanding of the structure–property relationship for utilizing efficient EDOT-bridged NFAs in high-performance OSC applications.

Charge transfer evidence in donor–acceptor single‐walled carbon nanotubes filled with sexithiophene oligomers: Nanotube diameter dependence

AbstractEncapsulation of photoactive organic molecules inside single‐walled carbon nanotubes (SWNTs) appears to be of great interest in terms of high power conversion efficiency and long‐term stability for a commercial application of organic solar cells (OSCs). In this paper, we report a charge transfer (CT) evidence in donor–acceptor SWNTs filled with Sexithiophene oligomers (6T) by Raman spectroscopy. To compute the optimal diameter and demonstrate the most stable structure of the hybrid systems with either a single 6T molecule encapsulated into SWNTs (6T@SWNTs), or two 6T chains encapsulated (6T‐6T@SWNTs), we have performed structural geometry optimization on the hybrid encapsulated systems using a convenient Lennard–Jones (LJ) expression of the van der Waals (vdW) intermolecular potential. Combining the density functional theory (DFT), molecular mechanics, bond polarizability model, and the spectral moment method (SMM), we computed the polarized nonresonant Raman spectra of 6T molecule and SWNTs (metallic and semiconducting) before and after encapsulation. The influence of the encapsulation on the Raman‐active modes of the 6T molecule and those of the nanotube (radial breathing modes and tangential modes) are analyzed. In particular, significant changes observed in the G‐band wavenumber. The possibility (or not) of an eventual CT between the 6T oligomer and the nanotube in both hybrid systems (6T@SWNTs and 6T‐6T@SWNTs) is discussed. We show that there is a dependence of the CT with respect to the diameter of SWNTs, the CT vanish with increasing diameter of the nanotubes. Our finding of CT behavior in the filled SWNTs with respect to SWNT diameter will provide a useful guidance for enhancing the performance of OSCs by SWNTs.

Molecular engineering of narrow bandgap porphyrin derivatives for highly efficient photothermal conversion

Organic dyes based on porphyrin derivatives have been widely reported to show promising application in dye-sensitized solar cells and organic solar cells due to their desired power conversion efficiency and extinction coefficient while their photothermal conversion performance is rarely reported, to date. Considering the design guideline of photothermal materials with wide near-infrared region absorption and large extinction coefficient, we designed and prepared a narrow bandgap donor-acceptor small molecule P(DPP)4 based on porphyrin and diketopyrrolopyrrole, which showed a photothermal efficiency of 73.2% under irradiation of 808 nm laser, due to its aggregation-induced radical and distinct nonradiative decay. Furthermore, in an interfacial-heating water evaporation system, P(DPP)4 exhibited an evaporation rate of 1.304 kg m−2 h−1 under 1 sun irradiation with a solar-energy-to-vapor efficiency of 90.6%, higher than most of the pure organic photothermal materials. This work provides a promising way for organic small molecules as solar absorbers with high solar-thermal conversion efficiency and reveals the great potential of organic semiconductors with aggregation-induced radical in photothermal materials.

Double-Cable Conjugated Polymers with Pendant Rylene Diimides for Single-Component Organic Solar Cells.

ConspectusConjugated polymers for application in organic solar cells (OSCs) have been developed from poly(phenylenevinylene) to poly(3-hexylthiophene) and then to "donor-acceptor" structures, providing power conversion efficiencies (PCEs) over 18% when blending with the electron acceptor as a two-component photoactive layer. Besides, graft-structural double-cable conjugated polymers that use an electron donor as conjugated backbones and an electron acceptor as pendant side units are one kind of conjugated polymer, in which charge carriers are generated in a single polymer. Therefore, double-cable conjugated polymers can be used as a single photoactive layer in single-component OSCs (SCOSCs). The covalently linked electron donor and acceptor enable double-cable polymers to maintain stable microstructures during long-term operation compared to two-component systems, which is very important for OSCs toward large-area applications. However, SCOSCs based on double-cable conjugated polymers provided PCEs below 3% in a long period, which is lagging far behind PCEs of two-component OSCs. The key reason for this is the limited number of chemical structures and the difficulty to tune the morphology in these polymers.In this Account, we provide an overview about our efforts on developing new double-cable conjugated polymers with rylene diimides as side units, and how to realize high PCEs in SCOSC devices. The studies start from developing a "functionalization-polymerization" method to synthesize the polymers containing rylene diimide acceptors, so that large amounts of double-cable conjugated polymers with distinct physical and electrochemical properties were obtained. Then, we will discuss how to control the nanophase separation in the crystalline region and optimize the miscibility in the amorphous region of double-cable polymers, simultaneously facilitating exciton dissociation and charge transport. With these efforts, a high PCE of 8.4% has been obtained, representing the record PCE in SCOSCs. In addition, the physical process and the stability of SCOSCs will be discussed. We hope that this account will inspire many innovative studies in this field and push the PCEs of SCOSCs to a new stage.