Efficiency Of Photovoltaic Cells Research Articles

Enhancing the efficiency of photovoltaic cells through the usage of dye concentrators

Over the past few years, there has been a growing interest in renewable energy sources. Among them, photovoltaic (PV) technology is advancing rapidly. Solar insolation is the most crucial factor for PV installations. Various solutions, such as tracking mechanisms, hybrid systems, and new materials, can enhance the efficiency of PV systems. Concentrators focus solar light onto the surface of solar modules, increasing production of electricity. Implementing such solutions can reduce the number of silicon cells in installations, leading to a decrease in waste generated during production. Dye concentrators have a positive impact on the performance of silicon systems. A two-stage study on the effect of dye concentrator application on PV cell efficiency is carried out. In the first stage, specific types of dye concentrators are tested for their interaction with the silicon system. Tinted and luminescent acrylic glass (polymethyl methacrylate, PMMA) in yellow and red are used as dye concentrators. The experiment included multiple measurement calibrations, such as the temperature of the tested silicon cell and the intensity of illuminance. Results showed absolute increase of efficiency in solar cells ranging from 0.05% to 1.42%, depending on the type of concentrator used. The most significant improvements were observed with luminescent red PMMA, averaging at 1.21%. The potential of this concentrator was further explored in the second stage of the study, investigating the relationship between the surface involvement of the silicon cell and the dye concentrator. Test results indicated the potential of dye concentrators for integrating luminescent dye concentrator technology into PV systems. The effect of this integration is increase in the efficiency of the PV cell. On the other hand, it should be noted that replacing the PV cell with a dye concentrator reduces the efficiency of the entire photovoltaic system. Hence, the use of a PV cell and concentrator system is recommended especially for photovoltaic systems with a large area. As dye concentrators have the ability to operate without direct irradiance, they are also recommended for regions where natural light is dispersed.

Study of the Effect of Exciton Annihilation Lifetime on Some Kinematic and Intrinsic Parameters of a Silicon Heterojunction Solar Cell (HIT), Illuminated by Monochromatic Light

In this article, with a view to improving the efficiency of photovoltaic cells, and given the promising yields of silicon heterojunction photovoltaic cells, we have, using a silicon heterojunction cell (a-Si:H/c-Si) doped with (n+p) , studied the contribution of excitons to the internal quantum efficiency of charge carriers. We then developed a detailed explanation of the energy conversion phenomena, based on an exciton-exciton annihilation process, which allows the electrons of quasiparticles to retain some of their energy. We used a numerical method for solving the charge carrier transport equations and carried out some additional calculations, which enabled us to obtain some results. These results then enabled us to study the influence of the annihilation lifetime on the charge carrier photo-current density, leading to internal charge carrier quantum yields of between 29.29768% and 77.8525%.

Boosting conversion efficiency by bandgap engineering of ecofriendly antimony trisulfide indoor photovoltaics via a modeling approach

With the exponential growth of the Internet of Things (IoT), indoor photovoltaics (IPVs) have emerged as a pivotal technology for powering low-power devices, drawing heightened interest due to their adaptability to indoor environments. The Photovoltaic Conversion Efficiency (PCE) of IPV cells is critically dependent on their ability to match the indoor spectrum with the device's response characteristics. In this realm, Antimony Trisulfide (Sb2S3), characterized by its wide bandgap and high absorption coefficient, emerges as a promising candidate for low-light applications. Our study focuses on the modeling and numerical analysis of Sb2S3 thin-film IPV cells by wxAMPS software, aiming to refine both the device structure and its photoelectric performance for effective indoor light harvesting. In a strategic shift from conventional CdS materials, we utilized SnO2—known for its high transmissivity, non-toxicity, and wide bandgap—as the electron transport layer (ETL) in Sb2S3 IPV cells. This substitution notably enhanced the short-wave response, elevating the spectral response from 45 % to 80 % at 400 nm. Additionally, we introduced a bandgap-tunable ZnOS buffer layer. This innovation proved instrumental in rectifying the band alignment mismatch between SnO2 and Sb2S3 layer, thereby optimizing interfacial electron transport properties. The integration of the ZnOS buffer layer effectively improved the fill factor from 40.0 % to 64.7 % of the Sb2S3 IPV cell by solving the band mismatch problem. The resulting optimized Sb2S3 IPV cell demonstrated exceptional response characteristics across the full visible spectrum (400–750 nm) and showed notable photoelectric performance under both fluorescent lamps (FLs) and light-emitting diodes (LEDs). Moreover, a detailed analysis was conducted on the performance differences of the device under indoor light sources compared to solar spectrum conditions, along with the underlying mechanisms. Finally, the Sb2S3 IPV cell achieved a peak theoretical efficiency of 46.25 % under cold white FL lighting, a testament to the optimal match between the device structure and this specific emission power spectrum. This modeling research not only underscores the feasibility of employing antimony-based photovoltaic technologies in indoor settings but also offers theoretical guidance for further advancements in this domain.

Side Connection for High‐Efficiency Organic Photovoltaic Modules for Indoor Applications: Shunt Reduction and Performance Improvement

Indoor photovoltaics has attracted increasing attention because of its potential to power devices of the Internet of Things. The power conversion efficiency (PCE) of organic photovoltaic (OPV) cells has reached values beyond 30% under indoor light, but for OPV modules it is still significantly lower. One reason is that the full width interconnection of sub‐cells in such modules. Here, a new side connection method is presented which significantly reduces shunts and thus improves performance of OPV modules for indoor applications where a large parallel resistance is crucial. To prove its advantage, OPV modules were fabricated on both Indium Tin Oxide (ITO) and ITO‐free substrates. Under 500 lux cool white LED light, the highest PCE of ITO‐free side connection modules (SCMs) is 15.1%, while for conventional full width connection modules (FWCMs) it is 14.4%. For ITO‐based modules under 1000 lux, it is 2.3% for FWCMs compared to 12.1% for SCMs. Thermography images show that the improvement stems indeed from the reduction of shunts. Finally, results from experiments as well as from numerical simulations illustrate clearly that efficiency losses stemming from the increased series resistance for the side connection are rather small and that they are overcompensated by the increased shunt resistance.This article is protected by copyright. All rights reserved.

Enhancing Solar Photovoltaic Cell Efficiency: A Comparative Analysis of Advanced Materials and Manufacturing Techniques

This research paper investigates the enhancement of solar photovoltaic (PV) cell efficiency through a comparative analysis of advanced materials and manufacturing techniques. With the escalating demand for renewable energy solutions, improving the efficiency of solar cells is paramount. This study focuses on several promising materials including silicon, perovskite, CIGS, organic, and dye-sensitized options, alongside innovative manufacturing techniques such as roll-to-roll printing, ultrasonic spraying, and laser scribing. The methodology employed an experimental approach, where various prototypes were fabricated and tested under controlled laboratory conditions. Regression analysis was utilized to examine the impact of different materials and manufacturing techniques on solar cell performance. Key findings revealed that specific manufacturing techniques, particularly laser scribing, significantly enhance the efficiency of silicon-based cells. Moreover, perovskite cells displayed robust performance under varied environmental conditions, suggesting their broader application potential. Material enhancements such as sodium doping in CIGS cells were also shown to substantially increase efficiency. The implications of these findings are significant, offering insights into the effective integration of materials and techniques that could lead to more cost-effective and efficient solar energy systems. This study not only advances the academic understanding of photovoltaic technologies but also guides practical implementations in the solar industry.

A theoretical investigation for improving the performance of non-fullerene organic solar cells through side-chain engineering of BTR non-fused-ring electron acceptors

In the current quantum chemical study, indacenodithiophene donor core-based the end-capped alterations of the reference chromophore BTR drafted eight A2-A1-D-A1-A2 type small non-fullerene acceptors. All the computational simulations were executed under MPW1PW91/6-31G (d, p) level of DFT. The UV–Vis absorption, open circuit voltage, electron affinity, ionization potential, the density of states, reorganization energy, orbital analysis, and non-covalent interactions were studied and compared with BTR. Several molecules of our modeled series BT1-BT8 have shown distinctive features that are better than those of the BTR. The open circuit voltage (VOC) of BT5 has a favorable impact, allowing it to replace BTR in the field of organic solar cells. The charge carrier motilities for proposed molecules generated extraordinary findings when matched to the reference one (BTR). Further charge transmission was confirmed by creating the complex with a PM6 donor molecule. The remarkable dipole moment contributes to the formation of non-covalent bond interactions with chloroform, resulting in superior charge mobility. Based on these findings, it can be said that every tailored molecule has the potential to surpass chromophore molecule (BTR) in OSCs. So, all tailored molecules may enhance the efficiency of photovoltaic cells due to the involvement of potent terminal electron-capturing acceptor2 moieties. Considering these obtained results, these newly presented molecules can be regarded for developing efficient solar devices in the future.

Sustainable coatings for green solar photovoltaic cells: performance and environmental impact of recyclable biomass digestate polymers

The underutilization of digestate-derived polymers presents a pressing environmental concern as these valuable materials, derived from anaerobic digestion processes, remain largely unused, contributing to pollution and environmental degradation when left unutilized. This study explores the recovery and utilization of biodegradable polymers from biomass anaerobic digestate to enhance the performance of solar photovoltaic (PV) cells while promoting environmental sustainability. The anaerobic digestion process generates organic residues rich in biodegradable materials, often considered waste. However, this research investigates the potential of repurposing these materials by recovering and transforming them into high-quality coatings or encapsulants for PV cells. The recovered biodegradable polymers not only improve the efficiency and lifespan of PV cells but also align with sustainability objectives by reducing the carbon footprint associated with PV cell production and mitigating environmental harm. The study involves a comprehensive experimental design, varying coating thickness, direct normal irradiance (DNI) (A), dry bulb temperature (DBT) (B), and relative humidity (C) levels to analyze how different types of recovered biodegradable polymers interact with diverse environmental conditions. Optimization showed that better result was achieved at A = 8 W/m2, B = 40 °C and C = 70% for both the coated material studied. Comparative study showed that for enhanced cell efficiency and cost effectiveness, EcoPolyBlend coated material is more suited however for improving durability and reducing environmental impact NanoBioCelluSynth coated material is preferable choice. Results show that these materials offer promising improvements in PV cell performance and significantly lower environmental impact, providing a sustainable solution for renewable energy production. This research contributes to advancing both the utilization of biomass waste and the development of eco-friendly PV cell technologies, with implications for a more sustainable and greener energy future. This study underscores the pivotal role of exploring anaerobic digestate-derived polymers in advancing the sustainability and performance of solar photovoltaic cells, addressing critical environmental and energy challenges of our time.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 7 Given name: [Ashok] Last name [Kumar Yadav]. Also, kindly confirm the details in the metadata are correct.correct

Improved performance of ternary organic solar cells based on both bulk and pseudo-planar heterojunction active layer

The high photovoltaic conversion efficiency (PCE) of ternary organic solar cells (OSCs) based on PTB7-Th, PC71BM and IEICO-4F material is obtained, the short-circuit current density (J SC), fill factor (FF), and open-circuit voltage is 25.90 mA cm−2, 73.20% and 0.71 V, respectively. PCE is as high as 13.53%. It is the highest PCE of ternary OSCs based on PTB7-Th, PC71BM and IEICO-4F materials for all we know. The narrow bandgap material of IEICO-4F is deposited on PTB7-Th:PC71BM bulk heterojunction (BHJ) by layer-by-layer process. We constructed the dual bandgap active layer both BHJ and pseudo-planar heterojunction (P-PHJ), it could be defined as ternary BHJ/P-PHJ of OSCs. This type of OSCs is not only the complementary bandgap material of the active layer, but also increasing the donor/acceptor (D/A) interface. The excitons generation and collection of the device are increased leading a higher J SC and FF. The semitransparent OSCs (ST-OSCs) is prepared by varying the thickness of Ag electrode and PCE can reach 9.70%, and the average visible light transmittance and light use efficiency of ST-OSCs are improved effectively.

Investigation on the Possibility of Improving the Performance of a Silicon Cell Using Selected Dye Concentrator

There are many opportunities to increase the efficiency of photovoltaic cells. These include solutions such as tracking mechanisms, hybrid systems or dye concentrators. Importantly, their implementation can reduce the number of silicon cells in installations, leading to reduced environmental impact. The principle of a dye concentrator is to focus sunlight onto the surface of PV modules, increasing electricity production. In this study, the potential for increased PV cell efficiency is investigated using a selected dye concentrator—tinted and luminescent acrylic glass (polymethylmethacrylate, PMMA) in yellow and red colors. The experiment included multiple measurement calibrations, such as the temperature of the silicon cell under test and the irradiation, as well as different variants of PV systems consisting of a silicon cell and different types of PMMA. Overall, the results show an increase in PV cell performance and the dependence of the increase on the type of PMMA used. The most favorable of the PV systems tested appeared to be the combination of a PV cell with a red luminescent PV, for which an average efficiency improvement of 1.21% was obtained.

Strain-Prompted Giant Flexo-Photovoltaic Effect in Two-Dimensional Violet Phosphorene Nanosheets.

As a second-order nonlinear optical phenomenon, the bulk photovoltaic (BPV) effect is expected to break through the Shockley-Queisser limit of thermodynamic photoelectron conversion and improve the energy conversion efficiency of photovoltaic cells. Here, we have successfully induced a strong flexo-photovoltaic (FPV) effect, a form of BPV effect, in strained violet phosphorene nanosheets (VPNS) by utilizing strain engineering at the h-BN nanoedge, which was first observed in nontransition metal dichalcogenide (TMD) systems. This BPV effect was found to originate from the disruption of inversion symmetry induced by uniaxial strain applied to VPNS at the h-BN nanoedge. We have revealed the intricate relationship between the bulk photovoltaic effect and strain gradients in VPNS through thickness-dependent photovoltaic response experiments. A bulk photovoltaic coefficient of up to 1.3 × 10-3 V-1 and a polarization extinction ratio of 21.6 have been achieved by systematically optimizing the height of the h-BN nanoedge and the thickness of VPNS, surpassing those of reported TMD materials (typically less than 3). Our results have revealed the fundamental relationship between the FPV effect and the strain gradients in low-dimensional materials and inspired further exploration of optoelectronic phenomena in strain-gradient engineered materials.

Patterned Liquid Crystal Polymer Thin Films Improved Energy Conversion Efficiency at High Incident Angles for Photovoltaic Cells.

In this report, micro-patterned silicon semiconductor photovoltaic cells have been proposed to improve the efficiency in various incident sunlight angles, using homeotropic liquid crystal polymers. The anisotropic liquid crystal precursor solution based on a reactive mesogen has good flowing characteristics. It can be evenly coated on the silicon solar cells' surface by a conventional spreading technique, such as spin coating. Once cured, the polymers exhibit asymmetric transmittance properties. The optical retardation characteristics of the coated polymer films can be eventually determined by the applicable coating and curing parameters during the processes. The birefringence of light then influences the optical path and the divergence of any encountered sunlight. This allows more photons to enter the active semiconductor layers for optical absorption, resulting in an increase in the photon-to-electron conversion, and thus improving the photovoltaic cell efficiency. This new design is straightforward and could allow various patterns to be created for scientific development. The experimental results have evidenced that the energy conversion efficiency could be improved by 2-3% for the silicon photovoltaic cells, under direct sunlight or at no inclination, when the liquid crystal polymer precursor solution is prepared at 5%. In addition, the efficiency could be much more significantly improved to 14-16% when the angle is inclined to 45°. The unique patterned liquid crystal polymer thin films provide enhanced energy conversion efficiency for silicon photovoltaic cells. The design could be further evaluated for other solar cell applications.

Research on the assessment of technical methods to suppress auger recombination

Human demand for fossil fuels has reached a very high level. However, fossil energy stocks are limited and, more importantly, their impact on the environment is increasing. The exploration of clean energy is particularly important. Among all the clean energy sources, solar energy is a very promising and important alternative to fossil fuels. And one of the primary reasons for the failure of solar photovoltaic cells to achieve rapid development is the generation of Auger composite. In order to provide support to solve this problem or facilitate the follow-up of researchers, this paper summarizes several effective methods such as Interfacial Engineering and Gradient Alloying to solve the Auger recombination problem in multi-exciton photovoltaic cells through reading and comparing a large number of relevant authoritative literature. The two methods mentioned above suppress Auger recombination by applying a new type of MXene (Nb2CTX-MXene) to the interface of SnO2 layers to pssivate the interfacial defects and promote charge transport and to generate InAs/CdSe core/shell QDs, overcoating InAs QDs with a lattice-matched CdSe shell. Comparing a large number of pieces of literature, it is found that the above two methods have guiding effects in improving the efficiency of photovoltaic cells.

Performance prediction of a novel solar power tower system based on spectral beam splitting

Photovoltaic technology is currently the most widely used solar generation technology in engineering. The particular spectral response band of PV cells cannot convert all solar radiation into electricity. Meanwhile, some radiation will become heat, leading to an increase in cell temperature and a decrease in the conversion efficiency of photovoltaic cells. Spectral splitting technology is an effective technology to improve electrical generation efficiency and can achieve full spectrum utilization of solar energy. The current work involved (1) proposing a novel solar power tower comprehensive utilization system based on spectral splitting; (2) developing a spectral splitting thin film configuration by using the Needle method whose transmittance is higher than 90% against the band range of 510 nm-1, 020 nm; (3) setting up a spectral splitting PV panel whose cover glass is coated the developed film, and replacing the heliostat of SPT system by using such spectral splitting PV panels; (4) predicting the electrical power generation of the spectral splitting-based tower type concentrating solar power system. The results demonstrate that the power generation efficiency of the proposed system is 5.5% and 3.46% higher than PV power generation and SPT systems respectively.

A Highly Efficient, Selective, and Thermally Stable Dielectric Multilayer Emitter for Solar Thermophotovoltaics

Herein, the design, optimization, fabrication, and characterization of a highly efficient selective emitter (SE) for solar thermophotovoltaic systems is presented. An SE consisting of three layers (SiNx–SiO2–TiO2) deposited on a tungsten substrate is optimized for use with photovoltaic (PV) cells based on III–V semiconductors, such as GaSb, InGaAs, and InGaAsSb. The fabricated SE shows an emitter efficiency (ηSE) of 50% when coupled with a PV cell having an energy bandgap of 0.63 eV. After thermal treatment carried out at 1000 °C for 8 h in a vacuum environment, ηSE of 46% is recorded, demonstrating the thermal stability of the proposed SE. Its behavior at high temperatures has also been studied using simulations based on the transfer matrix method and on refractive indices experimentally measured at different temperatures (up to 1000 °C). The results show ηSE of 44% in the energy bandgap range of 0.55–0.63 eV, proving that the proposed structure is promising and can operate at high temperatures. In addition, the behavior of a real PV cell is simulated, and calculations show a maximum PV cell efficiency of 15% at 1000 °C and 25% at 1600 °C, exceeding the Shockley–Queisser limit.

Highly Efficient and Stable Organic Photovoltaic Cells for Underwater Applications.

Organic photovoltaic (OPV) technology holds tremendous promise as a sustainable power source for underwater off-grid systems. However, research on underwater OPV cells is relatively scarce. Here, this gap is addressed by focusing on the exploration and development of OPV cells specifically designed for underwater applications. An acceptor, named ITO-4Cl, with excellent water resistance, is rationally designed and synthesized. Benefiting from its low energetic disorder and an absorption spectrum well-suited to the underwater environment, the ITO-4Cl-based OPV cell achieves an unprecedented power conversion efficiency (PCE) of over 25.6% at a water depth of 1m. Additionally, under 660nm laser irradiation, the cell demonstrates a notable PCE of 31.6%, indicating its potential for underwater wireless energy transfer. Due to the mitigation of thermal effects from solar irradiation, the lifetime of the ITO-4Cl-based OPV cell exceeds 7000h. Additionally, a flexible OPV cell is fabricated that maintains its initial PCE even under exposure to high pressures of 5MPa. A 32.5cm2 flexible module achieves an excellent PCE of 17%. This work fosters a deeper understanding of underwater OPV cells and highlights the promising prospects of OPV cells for underwater applications.

Enhancing photovoltaic cell efficiency: A comprehensive study on BN-Si3N4 blend antireflective coatings and their impact on power conversion

Antireflective surface coatings were one of the most important factors that contributed to the improvement of the functionality of photovoltaic cells. The coatings were performed by different methods such as RF sputtering, spin coating, dip coating, electro spraying etc. The coating materials such as BN, Si3N4 and BN-Si3N4 blends were applied to solar cells using the RF sputtering technique in this study. Several distinct characterization methods were adopted to assess the productivity of Si3N4 coated cells. The BN-Si3N4 blend coated cell has a low light reflection of 8 % and exhibits uniform layer deposition, which shows a significant improvement over conventional solar cell. The BN-Si3N4 solar cell was able to obtain the highest possible power conversion efficiency of 19.70 % when exposed to direct sunlight and 21.28 % when exposed to neodymium light. It possess the narrow scope of visible spectrum and acts as green/yellow filter in visible spectrum. This light is capable of delivering light similar to sunlight with consistent radiation. This was accomplished by increasing the transmission of photons that reached the depletion region. The four-probe experiment was employed to measure the electrical resistivity of BN-Si3N4 solar cell, which was found to be 0.00298 Ω-cm. This value was lower than the electrical resistivity of other solar cell samples. Based on the results, BN-Si3N4combination outperformed both coated and bare cells. It was found that BN-Si3N4blendwas a remarkable antireflective coating to maximize the performance.

Improving vapor condensation via copper foam in capillary-fed photovoltaic membrane distillation

The photovoltaic conversion efficiency of solar cells is significantly constrained by temperature rise. Photovoltaic membrane distillation (PVMD) offers a promising solution for simultaneous solar cell cooling and clean water production. However, the present PVMD system is confronted with the challenge of attaining high cooling efficiency and water production sans reliance on fossil fuels. In this work, a novel and zero-carbon PVMD system is introduced and optimized. One notable improvement is the transportation of feedwater to the backside of the solar cell using capillarity instead of a pumping system. Additionally, a porous copper foam condenser with a rough surface is introduced to the PVMD system. This rough surface creates more nucleation sites for rapid vapor condensation, resulting in a water productivity increase from 0.23 to 0.43 kg m−2 h−1 under 1 sun (=1 kW m−2) irradiation. Furthermore, a 5 cm × 5 cm solar cell demonstrates a temperature decrease from 59.9 to 38.3 °C, accompanied by a voltage enhancement from 2.18 to 2.39 V. This work offers an effective strategy for lowering the operational temperature of solar cells and enhancing the overall utilization efficiency of PVMD devices.

Molecular Design of Fully Nonfused Acceptors for Efficient Organic Photovoltaic Cells.

The nonfused thiophene-benzene-thiophene (TBT) unit offers advantages in obtaining low-cost organic photovoltaic (OPV) materials due to its simple structure. However, OPV cells, including TBT-based acceptors, exhibit significantly lower energy conversion efficiencies. Here, we introduce a novel approach involving the design and synthesis of three TBT-based acceptors by substituting different position-branched side chains on the TBT unit. In comparison to TBT-10 and TBT-11, TBT-13, which exclusively incorporates α-position branched side chains with a large steric hindrance, demonstrates a more planar and stable conformation. When blended with the donor PBQx-TF, TBT-13-based blend film achieves favorable π-π stacking and aggregation characteristics, resulting in excellent charge transfer performance in the corresponding device. Due to the simultaneous enhancements in short-circuit current density and fill factor, the TBT-13-based OPV cell obtains an outstanding efficiency of 16.1%, marking the highest value for the cells based on fully nonfused acceptors. Our work provides a practical molecular design strategy for high-performance and low-cost OPV materials.

A numerical study on the effect of employing porous medium on thermal performance of a PV/T system

Surface temperatures of photovoltaic (PV) panels increase with solar radiation and ambient temperature. This temperature increase negatively affects the PV cell, causing the electrical efficiency of the system to decrease. Photovoltaic-thermal (PV/T) systems also provide thermal energy gain by cooling PV cells, increasing electrical conversion efficiency and lifespan. Integrating porous material into cooling pipes offers an important innovation in terms of the cooling techniques of PV panels. This study emphasizes the positive effects of porous materials by innovative approaches in this field. For this reason, in order to increase the electrical and thermal efficiency of PV cells, a porous material-supported cooling system was designed for the PV/T system and the effects of using porous materials with different properties were examined with Ansys Fluent software. As the porous density and porosity ratio of the porous material used throughout the pipe decreased, the average cell temperature decreased and the water outlet temperature increased. At a low flow rate of 0.3 L/min, it achieved an improvement of approximately 118% in thermal efficiency compared to the pipe without porous material. The porous structure containing 0.9 and 30 PPI pore density reached the highest efficiency value of 96.56% with a flow rate of 1.71 L/min.

Design and Synthesis of Dibenzothiadiazolopyrrolothiophene (DBTPT)‐Based Acceptors for Efficient Organic Photovoltaic Cells

AbstractThe central core in non‐fullerene acceptors (NFAs) plays a crucial role in determining the efficiency of organic photovoltaic (OPV) cells. To further advance the development of OPV cells, it is crucial to synthesize novel central cores for constructing high‐performance NFAs. Here, dibenzothiadiazolopyrrolothiophene (DBTPT) is introduced, a ladder‐type [1,2,5]thiadiazolo[3,4‐e]indole‐fused pentacyclic thiophene unit, into photovoltaic materials. By employing the DBTPT unit as the rigid molecular backbone and modifying the side chain of the thiophene π‐bridge, two new acceptor‐π‐acceptor’‐donor‐acceptor’‐π‐acceptor (A‐π‐A'DA’‐π‐A)‐type acceptors (T6 and T9) are synthesized. The effects of lateral alkyl and alkoxy side chains on the optoelectronic properties, charge transport, and molecular packing order are systematically investigated. When blended with polymer donor 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), the blend film based on T9 with alkoxy side chains shows favorable molecular stacking and phase separation, resulting in excellent charge transfer performance. Benefiting low energetic disorder, PBDB‐T:T9‐based cell achieves an efficiency of 12.6% with a markedly low energy loss of 0.568 eV. The preliminary results demonstrate that the DBTPT unit has great potential for the construction of novel NFAs for high‐performance OPV cells.