Enhancement Of Absorption Coefficient Research Articles

Optimizing phase formation of BiFeO3 and Mn-doped BiFeO3 nanoceramics via thermal treatment using citrate precursor method

In recent years, bandgap tailoring of ferroelectric materials has gained great attention in the scientific community owing to their favourable materials characteristics, and new endowing paths for developing multifunctional devices. In this study, an attempt was made to tune the optical bandgap of BiFeO3 (BFO) via chemical substitution and by controlling thermal treatment temperature and time. A series of BiFe1-xMnxO3 (x = 0.00, 0.03, 0.05) nanoceramic samples were prepared by adopting the citrate precursor method. The effect of Mn substitution, annealing temperature, and annealing time on structural, morphological, and optical properties of BFO was investigated using X-ray diffraction, field emission scanning electron microscopy, and UV–visible spectroscopy, respectively. The average crystallite size was found to decrease (from 44−17 nm) with Mn-doping and increase with increasing annealing temperature and time (from 17−27 nm) due to the agglomeration of nanoparticles. The FESEM studies revealed the inhomogeneous distribution of granular structured grains with negligible porosity. The optical bandgap energy of BFO nanoparticles was found to reduce significantly by 21% (2.08−1.62 eV) with a competing effect of Mn-substitution, annealing temperature, and annealing time. The optical bandgap studies of BiFe0.97Mn0.03O3 showed a direct correlation with annealing temperature and an inverse correlation with annealing time. Additionally, BiFe0.97Mn0.03O3 nanoparticles annealed at 550 °C for 2 h showed a 31% enhancement in absorption coefficient and 14% reduction in bandgap value without a structural phase transition. The results obtained in this study propose BiFe0.97Mn0.03O3 nanoparticles as a potential candidate for upcoming ferroelectric photovoltaic devices.

Fluorinated benzotriazole-modified random terpolymer acceptors towards less thickness-sensitive all-polymer solar cells

Naphthalene diimide (NDI)-based n-type polymers have been reported as the most widely employed polymer acceptors so far. However, all-polymer solar cells (all-PSCs) based on NDI-typed acceptors commonly suffer from low short-circuit current density (Jsc) due to the deficient absorption coefficients of polymer acceptors and unsatisfactory morphologies. In this work, based on the most widely used copolymer acceptor N2200, we designed terpolymer acceptors named PNDI-BTzx (x = 5 and 10) by randomly embedding a certain amount of fluorinated benzotriazole (2f-BTz) into N2200 backbone. The enhanced absorption coefficients, relatively weakened polymer crystallinities and improved polymer miscibility were obtained from terpolymer acceptors compared to N2200. Synchronously benefited from improved absorption and optimized morphology, all-PSCs based on PNDI-BTz5 demonstrated enhanced photovoltaic performance with power conversion efficiency (PCE) and Jsc of 6.72% and 12.54 mA cm−2 than 5.67% and 10.80 mA cm−2 from N2200-control. In addition, satisfactory reproducibility was obtained with comparable performance among different batches of PNDI-BTzx (x = 5 and 10). And more interestingly, all-PSCs based on PNDI-BTz5 possessed better thickness tolerance than N2200. These results offered useful guidelines to realize reproducible-performance and thick-film practical all-polymer photovoltaic applications through designing random terpolymer acceptors.

Exploring a Fused 2-(Thiophen-2-yl)thieno[3,2-b]thiophene (T-TT) Building Block to Construct n-Type Polymer for High-Performance All-Polymer Solar Cells.

In the field of all-polymer solar cells, exploring new electron-donating units (D) to match with electron-accepting units (A) is an important subject to promote the performance of D-A-type polymer acceptors. Herein, we developed a fused D unit 2-(thiophen-2-yl)thieno[3,2-b]thiophene (T-TT) derivated from the famous 2-(2-(thiophen-2-yl)vinyl)thiophene (TVT) unit. With classical naphthalene diimide (NDI) as A unit, the new D-A polymer PNDI-T-TT exhibits enhanced absorption coefficient, electron mobility, and miscibility with donor polymer in comparison with the analogous PNDI-TVT polymer. These advantages can be attributed to the enlarged conjugation and reduced rotamers due to the fused T-TT unit, leading to a stronger intermolecular interaction. When blending with the donor polymer PBDB-T, both NDI-based polymers can form better interpenetrating nanostructures than the corresponding blend films with the donor polymer J71. Finally, PBDB-T/PNDI-T-TT device achieves a power conversion efficiency of 6.1%, which is much higher than that of PBDB-T/PNDI-TVT device (4.24%). These results demonstrate that n-type polymer based on fused T-TT unit can ameliorate the absorption coefficient, molecular aggregation, and charge-carrier mobility and consequently achieve an improved photovoltaic performance in comparison with the classic TVT unit.

Investigation of the Broadband Microwave Absorption of Citric Acid Coated Fe3O4/PVDF Composite Using Finite Element Method

Magnetite (Fe3O4) have been thoroughly investigated as microwave absorbing material due to its excellent electromagnetic properties (permittivity and permeability) and favorable saturation magnetization. However, large density and impedance mismatch are some of the limiting factors that hinder its microwave absorption performance (MAP). Herein, Fe3O4 nanoparticles prepared by facile co-precipitation method have been coated with citric acid and embedded in a polyvinylidene fluoride (PVDF) matrix. The coated Fe3O4 nanoparticles were characterized by X-ray diffraction spectrometer (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and vibrating sample magnetometer (VSM). COMSOL Multiphysics based on the finite element method was used to simulate the rectangular waveguide at X-band and Ku-band frequency range in three-dimensional geometry. The citric acid coated Fe3O4/PVDF composite with 40 wt.% filler loading displayed good microwave absorption ability over the studied frequency range (8.2–18 GHz). A minimum reflection loss of −47.3 dB occurs at 17.9 GHz with 2.5 mm absorber thickness. The composite of citric acid coated Fe3O4 and PVDF was thus verified as a potential absorptive material with improved MAP. These enhanced absorption coefficients can be ascribed to favorable impedance match and moderate attenuation.

First-principles prediction of the electronic, magnetic and optical properties of N, P, As-doped marcasite FeS2

Using the first-principles calculations, the electronic, magnetic and optical properties of non-metal (N, P or As) doped marcasite FeS2 (m-FeS2) have been investigated. It is feasible to combine N, P or As atoms into m-FeS2 experimentally under Fe-rich condition due to the negative formation energies. The spin stability calculations indicate that the three doped systems prefer spin polarized state. The substitutional doping of the N, P or As atom at S site can induce magnetism in m-FeS2 and the total magnetic moments of the three doped systems are all nearly 1μB, this is caused by one hole introduced by the dopants. Both N- and P-doped m-FeS2 systems show spin-gapless character while As-doped m-FeS2 system exhibits half-metallic feature. In addition, compared with the pristine m-FeS2, the P- or As-doped m-FeS2 systems have not only an enhanced absorption coefficient but also a red shift phenomenon. So the P- or As-doped m-FeS2 systems can be used in optoelectronic device.

A Terminally Tetrafluorinated Nonfullerene Acceptor for Well‐Performing Alloy Ternary Solar Cells

AbstractFabricating ternary solar cells is a pivotal strategy to improve the power conversion efficiencies (PCEs) of organic photovoltaic devices. However, it is still a challenge to simultaneously improve the performance parameters of ternary devices. Therefore, the third ingredient in ternary blends should be precisely designed or selected. Herein, a new medium‐bandgap small‐molecule acceptor, namely, 3,9‐bis(2‐methylene‐(3‐(1‐(3,5‐dimethylphenyl)‐1cyanomethylene)indanone))‐5,5,11,11‐tetrakis‐(4‐hexylphenyl)dithieno[2,3‐d:2′,3′‐d′]‐sindaceno[1,2‐b:5,6‐b′]dithiophene (ITIF), is synthesized by end‐capping with a new fluorinated, asymmetric terminal group, (Z)‐2‐(3,5‐difluorophenyl)‐2‐(3‐oxo‐2,3‐dihydro‐1H‐inden‐1‐ylidene) acetonitrile. Replacing the CN substituent with the asymmetric 3,5‐difluorophenyl substituent obviously up‐shifts the lowest unoccupied molecular orbital (LUMO) level of ITIF to −3.78 eV, enlarges the bandgap to 1.82 eV, and improves the absorption coefficient to ≈50% higher than that of 3,9‐bis(2‐methylene‐(3‐(1,1‐dicyanomethylene)indanone))‐5,5,11,11‐tetrakis‐(4‐hexylphenyl)dithieno[2,3‐d:2′,3′‐d′]‐sindaceno[1,2‐b:5,6‐b′]dithiophene (ITIC). Due to the similar structures, ITIF and ITIC can combine as an alloyed acceptor, which makes it convenient to tune the morphology and optical and electrochemical properties of ternary blends. The enhanced absorption coefficient of ITIF and the rapid fluorescence resonance energy transfer from ITIF to ITIC remarkably improve the absorption of the ternary blend film, hence compensating for the external quantum efficiency (EQE) curves. When ITIF is introduced into ternary solar cells based on poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b′]dithiophene))‐alt‐(5,5‐(1′,3′‐di‐2‐thienyl‐5′,7′‐bis(2‐ethylhexyl)benzo[1′,2′‐c:4′,5′‐c′]dithiophene‐4,8‐dione)] (PBDB‐T):ITIF:ITIC blends, the PCEs of the ternary devices are increased from 9.2% to 10.5%, and the short‐circuit currents, open‐circuit voltages, and fill factors are simultaneously improved.

FEM Model of the Temperature Distribution in the Brain during Enhanced Infrared Neural Stimulation Using Nanoparticles

Objectives: Enhanced infrared neural stimulation (EINS) using nanoparticles is a new research hotspot. In this paper, the numerical modeling of the interaction between a light source and brain tissue during EINS is studied. Materials and Methods: This model is built with the finite element method (FEM) to mimic the propagation and absorption of light in brain tissue with EINS. Only the thermal change is considered in this model since the photothermal effect is the main mechanism of EINS. The temperature response of brain irradiation is governed by the extensively used Pennes’ bio-heat equation in a multilayer model. Results: The temperature distribution in the brain under laser irradiation is determined. And the relationships between the brain tissue temperature and the three factors (the laser pulse time, the laser energy and the enhanced absorption coefficient of the tissue caused by the nanoparticles) are analyzed. Conclusions: The results indicate that the brain tissue is easier to warm up with the enhancement of nanoparticles and parameters of the laser can alter the temperature increase of the brain tissue. These findings offer a theoretical basis for future animal experiments.

Chalcogens doped BaTiO3 for visible light photocatalytic hydrogen production from water splitting.

The pristine BaTiO3 has been experimentally confirmed to catalyze hydrogen production from water splitting, but the reaction cannot be driven by the visible light because of the wide energy band gap of BaTiO3. To understand the feasibility of the reaction driven by the visible light of the strongest part of the solar energy, we have investigated the effect of different concentrations of oxygen group element dopants on the electronic and optical properties of BaTiO3 by using first-principles density functional theory calculations with meta-GGA + MBJ potential. The formation energy of each doped structure is calculated to examine the feasibility of synthesis in energy. The energy band gaps and the energy positions of conduction and valence bands are calculated and the results reveal that all the structures except the one that doped with 5 at% Te satisfy the conditions of water splitting although the energy band gaps of the doped BaTiO3 decrease obviously. The partial charge distributions of conduct band maximum and valence band minimum are used to demonstrate the electron-hole separation. The absorption coefficients are calculated for all the considered structures. The results demonstrate that the doped chalcogens can significantly enhance the absorption in visible light range, which implies that the doped BaTiO3 are promising to catalyze the hydrogen production from water splitting driven by solar energy.

Synthesis, structure and photophysical properties of dibenzofuran-fused boron dipyrromethenes

Regioselective functionalization of core per-substituted boron dipyrromethenes (BODIPYs) has been achieved efficiently based on tetrabromoBODIPY, which affords a series of dibenzofuran-fused chromophores, via a regioselective nucleophilic substitution reaction followed by direct palladium-catalyzed two-fold intramolecular ring fusion. These rigid dibenzofuran-fused BODIPYs showed impressive photophysical properties such as clearly red-shifted absorption and emission bands, enhanced absorption coefficients upon and intense fluorescence (close to unity).

Photonic enhanced thin-film solar cells with conformal nanostructure

The interaction between light and photonic nanostructures is highly promising for light management applied to thin-film solar cells (TFSC). In this work, we introduce a strategy on conformal TFSCs on periodic nanostructures. A cost-effective self-assembly approach was used to fabricate monolayers SiO2 spherical arrays of different diameters. The structural parameters were adjusted by plasma etching procedure. Obviously, far-field light trapping properties were identified in optical performance. The conformal structure was realized in the post-deposited a-Si:H absorber layer. Photonic enhanced guided resonances were identified through finite-difference-time-domain simulation, resulted in an enhanced absorption coefficient both theoretically and experimentally. The near-field optical performance makes 500 nm SiO2 nanoparticles a promising choice for TFSC applications. To leverage the benefits of the photonic enhanced behavior, an a-Si:H solar cell with conformal nanostructure was fabricated as the first demonstration. Enhanced absorption was exhibited over the entire wavelength range. As a result, the photonic enhanced a-Si:H solar cell with conformal nanostructure based on ranged SiO2 nanospheres yielded a broadband light-management promotion, and improved the overall external quantum efficiency by 20% and 2.7%, respectively in comparison to the planar and textured AZO referenced. These results provide a promising platform for future development of cost-effective photonic enhanced nanostructured optoelectronic devices with efficient broadband light management.

Optimized Ge1−<italic>x</italic>Sn<italic>x</italic>/Ge Multiple-Quantum-Well Heterojunction Phototransistors for High-Performance SWIR Photodetection

We present the design and analysis of three-terminal Ge1− x Sn x /Ge multiple-quantum-well (MQW) heterojunction phototransistors (HPTs) for high-performance short-wave infrared (SWIR) photodetection. The active layer incorporates Ge1− x Sn x /Ge MQW structures between base–collector junctions pseudomorphically grown on Ge-on-Si substrates, thereby providing compatibility with CMOS platforms for low cost and scalable manufacturing technology. Introducing Sn into the MQW structures can effectively reduce the direct bandgap, thereby considerably extending the photodetection range in the SWIR spectral range with improved absorption efficiencies. In addition, the use of MQW structures as the active layer can enhance the absorption coefficient via quantum-confinement effects, thus further enhancing the photoresponses. We develop theoretical models to calculate the strained electronic band structures and optical absorption coefficients for the Ge1− x Sn x /Ge MQW structures, and the current gain is evaluated as a function of the barrier/well thicknesses, number of periods of the MQW structures, and doping concentrations of the layers for the HPT structures. The calculation results show that the absorption coefficient can be significantly enhanced by increasing the Sn content in the Ge1− x Sn x /Ge MQW active layer, and the current gain can be considerably enhanced by optimizing the HPT structures. With the enhanced absorption coefficient and current gain, high-responsivity photodetection can be achieved in the SWIR spectral range, thus making this device very promising for a wide range of SWIR photodetection applications.

Quadrupolar D–A–D diketopyrrolopyrrole-based small molecule for ternary blend polymer solar cells

A quadrupole diketopyrrolopyrrole (DPP)-based small molecule (DPP4T-Cz) was designed and synthesized to enhance absorption coefficient, and then employed as the third component to improve the light harvesting of polymer solar cells based on a blend of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). Because of an enhanced absorption coefficient of more than 105 cm−1, the photon harvesting efficiency was improved effectively in the near infrared (near-IR) range by using only a small amount of DPP4T-Cz (3.4 wt%) into the P3HT:PCBM binary blend polymer solar cells. Interestingly, the photocurrent generation was also enhanced in the visible range by the long-range energy transfer from P3HT to DPP4T-Cz molecules. As a result, the short-circuit current density (JSC) and power conversion efficiency (PCE) of P3HT:PCBM:DPP4T-Cz ternary blend devices were enhanced by more than 30% compared to those of P3HT:PCBM binary control devices. These findings suggest that quadrupole DPP-based molecules are one of the effective light-harvesting materials for ternary blend polymer solar cells.

Visible light driven photocatalyst of vanadium (V3+) doped TiO2 synthesized using sonochemical method

TiO2 has been widely investigated due to its superior photocatalytic activity under ultraviolet irradiation among the photocatalyst materials. In this research, vanadium (V3+) was doped into TiO2 to enhance its light response under visible irradiation for wider application. Vanadium was introduced into TiO2 lattice at various concentration respectively 0.3, 0.5, 0.7 and 0.9% using simple and fast sonochemical method. X-Ray Diffraction data show that vanadium doped TiO2 crystallized in anatase phase with I41amd space group. X-Ray Diffraction pattern shifted to lower value of 2θ due to vanadium dopant. It indicated that V3+ was incorporated into anatase lattice. UV-Vis Diffuse Reflectance Spectra was revealed that the doped TiO2 has lowered reflectance and enhanced absorption coefficient in visible region than undoped TiO2 and commercial anatase TiO2. Band gap energy for undoped and doped TiO2 were respectively 3.22, 3.05, 2.93, 3.03 and 2.40 eV. Therefore vanadium doped TiO2 had potential to be applied under visible light.

Synthesis, optical properties and theoretical modelling of discrete emitting states in doped silicon nanocrystals for bioimaging.

The creation of multiple emission pathways in quantum dots (QDs) is an exciting prospect with fundamental interest and optoelectronic potential. For the first time, we report multiple emission pathways in semiconductor nanocrystals (NCs) where the number of emission pathways desired is controlled by the number of dopant atoms per quantum dot. The origin of additional emission pathways is explained by interactions between dopant states and NC energy levels. Density functional theory (DFT) calculations of undoped 2.3 nm silicon (Si NCs) and the same NCs doped with 2 interstitial Cu atoms show good agreement to experiment. Such calculations provide valuable data to explain the changes in optical transitions due to the Cu dopant in terms of transition energies, quantum yield and dopant position as a function of dopants per NC. Changes in the optical properties of Si NCs induced by dopant concentration include extended excitation range and enhanced absorption coefficients, emission redshifts of up to 60 nm, and a two-fold increase in quantum yields up to 22%. The optical properties of doped NCs lead to significant bioimaging improvements illustrated by in vitro cell imaging, including redshifted excitation wavelengths away from natural autofluorescence and enhanced fluorescent signals.

Anomalous light-to-electricity conversion of low dimensional semiconductor in p-n junction and interband transition quantum well infrared detector

Recently, high localized carrier extraction efficiency and enhanced absorption coefficient were observed in low-dimensional semiconductor within a p-n junction. In this work, we report the discovery and verification of the phenomenon, and the performance of the first photon detector based on the interband transition of strained InGaAs/GaAs quantum wells (QWs). By introducing the resonant excitation photoluminescence, the same phenomena are observed in several different material systems. More than 95% of the photoexcited carriers escape from InGaN/GaN QWs, and 87.3% in InGaAs/GaAs QWs and 88% in InAs/GaAs quantum dots are observed. The external quantum efficiency of the device is measured to be 31% by using an absorption layer with only 100 nm effective thickness in the case without an anti-reflection layer. Using such a high value of quantum efficiency, an absorption coefficient of 3.7104 cm-1 is calculated, which is obviously larger than previously reported values. The results here demonstrate the possibility of fabricating high-performance and low-cost infrared photon detectors.

Comparative study of electronic and optical properties of graphene and germanene: DFT study

We have performed a first-principle study of the electronic and optical properties of optimized structure of germanene and graphene by means of density functional theory, using the full potential linearized augmented plane wave (FP-LAPW) method based to Gradient Generazed approximation (GGA). Moreover, the enhanced absorption coefficient, reflectivity and refraction index are also study in both directions. In general, the calculated results indicate that the graphene and germanene are similar electronic structure with zero band gap at K point, further the absorption coefficient and reflectivity of germanene is higher in visible light than graphene; germanene holds great potential solar cell applications.

High power conversion efficiency of intermediate band photovoltaic solar cell based on Cr-doped ZnTe

We report on a high-performance intermediate band solar cell (IBSC) based on Cr-doped ZnTe (ZnTe:Cr) fabricated using a pulsed laser deposition (PLD) method. Chromium (Cr) was uniformly distributed in the ZnTe:Cr thin film with an atomic concentration of about 3.5%, and the ZnTe:Cr thin film showed p-type electrical conductivity. The ZnTe:Cr thin film had higher absorption coefficients than those of undoped ZnTe films in the photon energy range below band gap of ZnTe (2.2eV). The enhanced absorption coefficients of the ZnTe:Cr thin film were attributed to the photoionization energy between Cr2+ and Cr+ (Cr2+⇌ Cr+), which acted as the IB to absorb photons below the bandgap of ZnTe (2.2eV). Illumination with an AM 1.5G solar spectrum on the ZnTe:Cr IBSC generated a large short circuit current of 21.18mA/cm2, an open circuit voltage of 0.48V, and a fill factor of 0.58, yielding a power conversion efficiency (PCE) of 5.9%, the highest reported PCE in an IBSC based on impurity-doped ZnTe.

Guest Hydrogen Bond Dynamics and Interactions in the Metal–Organic Framework MIL-53(Al) Measured with Ultrafast Infrared Spectroscopy

MIL-53(Al) is among the most “flexible” metal–organic frameworks and significantly changes its structure when guest molecules are introduced into the framework’s pores. The guest molecules interact with μ2-OH, which is a hydroxyl group bridging two aluminums. This interaction is thought to play an important role in the adsorption of molecules into the pores. Here, we report infrared absorption, infrared pump–probe, and two-dimensional infrared spectroscopy on a deuterated bridging hydroxyl, μ2-OD, in MIL-53(Al) loaded with various guest molecules. Depending on guest, large vibrational frequency shifts, broadening of absorption band, enhancement of absorption coefficient, and acceleration of vibrational relaxation were observed, which are all signatures of hydrogen bonding interactions between the bridging hydroxyls and the guest. 2D IR spectroscopy reveals that the time evolution of the vibrational frequency occurs on multiple time scales: subpicosecond dynamics caused by localized hydrogen bond fluctuati...

Enhanced photovoltaic performance of polymer-filled nanoporous Si hybrid structures.

We propose a novel hybrid structure for improving the efficiency of crystalline silicon solar cells. By employing first-principles calculations, we demonstrate that ordered, nanoporous silicon (np-Si), when filled with polythiophene (PT) inside the pores, exhibits a substantially enhanced absorption coefficient compared to both np-Si and the bulk, which makes the np-Si/PT heterojunction a superior light absorbing material. In addition, the PT-filled porous structure forms a staggered gap, or type II, heterojunction at the interfaces, where the valence band maximum and conduction band minimum of the composite reside on PT and np-Si, respectively. Moreover, the pore-filling polymer brings about a highly dispersive valence band, which provides a major pathway for hole transport. These results suggest that such a hybrid structure, which may be easier to scale up than nanowire-based approaches, will efficiently dissociate photo-induced electron-hole pairs and reduce the amount of material for light absorption, thus leading to a cost-effective and high-performance solar cell.

Improved Performance of Ternary Polymer Solar Cells Based on A Nonfullerene Electron Cascade Acceptor

Efficient ternary polymer solar cells are constructed by incorporating an electron‐deficient chromophore (5Z,5′Z)‐5,5′‐((7,7′‐(4,4,9,9‐tetrakis(4‐hexylphenyl)‐4,9‐dihydro‐s‐indaceno[1,2‐b:5,6‐b′]dithiophene‐2,7‐diyl)bis(6‐fluorobenzo[c][1,2,5]thiadiazole‐7,4‐diyl))bis(methanylylidene))bis(3‐ethyl‐2‐thioxothiazolidin‐4‐one) (IFBR) as an additional component into the bulk‐heterojunction film that consists of a wide‐bandgap conjugated benzodithiophene‐alt‐difluorobenzo[1,2,3]triazole based copolymer and a fullerene acceptor. With respect to the binary blend films, the incorporation of a certain amount of IFBR leads to simultaneously enhanced absorption coefficient, obviously extended absorption band, and improved open‐circuit voltage. Of particular interest is that devices based on ternary blend film exhibit much higher short‐circuit current densities than the binary counterparts, which can be attributed to the extended absorption profiles, enhanced absorption coefficient, favorable film morphology, as well as formation of cascade energy level alignment that is favorable for charge transfer. Further investigation indicates that the ternary blend device exhibits much shorter charge carrier extraction time, obviously reduced trap density and suppressed trap‐assisted recombination, which is favorable for achieving high short‐circuit current. The combination of these beneficial aspects leads to a significantly improved power conversion efficiency of 8.11% for the ternary device, which is much higher than those obtained from the binary counterparts. These findings demonstrate that IFBR can be a promising electron‐accepting material for the construction of ternary blend films toward high‐performance polymer solar cells.