Chen Weijie

Publication date: February 2023

Source: Journal of Energy Chemistry, Volume 77

Author(s): Jian Yang, Jianfei Hu, Wenhao Zhang, Hongwei Han, Yonghua Chen, Yue Hu

A series of cadmium halides are introduced on the surface of SnO₂ electron transport layer (ETL), both SnO₂ and CsPbI₂Br films are modified by dual direction thermal diffusion treatment, so that SnO₂ ETL with better matching energy levels and CsPbI₂Br films with fewer defects are obtained. Finally, a carbon-based CsPbI₂Br PSCs with a PCE of 14.47% is obtained.

Abstract

In recent years, carbon-based CsPbI₂Br perovskite solar cells (PSCs) have attracted more attention due to their low cost and good stability. However, the power conversion efficiency (PCE) of carbon-based CsPbI₂Br PSCs is still no more than 16%, because of the defects in CsPbI₂Br or at the interface with the electron transport layer (ETL), as well as the energy level mismatch, which lead to the loss of energy, thus limiting PCE values. Herein, a series of cadmium halides are introduced, including CdCl₂, CdBr₂ and CdI₂ for dual direction thermal diffusion treatment. Some Cd²⁺ ions thermally diffuse downward to passivate the defects inside or on the surface of SnO₂ ETL. Meanwhile, the energy level structure of SnO₂ ETL is adjusted, which is in favor of the transfer of electron carriers and blocking holes. On the other hand, part of Cd²⁺ and Cl⁻ ions thermally diffuse upward into the CsPbI₂Br lattice to passivate crystal defects. Through dual direction thermal diffusion treatment by CdCl₂, CdI₂ and CdBr₂, the performance of devices has been significantly improved, and their PCE has been increased from 13.01% of the original device to 14.47%, 14.31%, and 13.46%, respectively. According to existing reports, 14.47% is one of the highest PCE of carbon-based CsPbI₂Br PSCs with SnO₂ ETLs.

A hinge-type fluorine-rich complex cobalt (II) hexafluoro-2,4-pentanedionat (CoFAc) is developed to optimize the interface of FACsPbI₃/Spiro-OMeTAD, which can passivate both organic cations and halide anion vacancies on perovskite surface, and enhance interfacial hole-transport kinetics by interaction with Spiro-OMeTAD. Consequently, CoFAc-modified FACsPbI₃ solar cells yield a respectable PCE of 24.64%, a record V _oc of 1.191 V, and excellent stability.

Abstract

High density of defects at interface severely affects the performance of perovskite solar cells (PSCs). Herein, cobalt (II) hexafluoro-2,4-pentanedionat (CoFAc), a hinge-type fluorine-rich complex, is introduced onto the surface of formamidinium cesium lead iodide (FACsPbI₃) film to address the issues of perovskite/Spiro-OMeTAD interface. The existence of CoFAc passivates both organic cation and halide anion vacancies by establishing powerful hydrogen bonds with HC(NH₂)₂ ⁺ (FA⁺) and strong ionic bonds with Pb²⁺ in perovskite films. In addition, CoFAc serves as a connecting link to enhance interfacial hole-transport kinetics via interacting with Spiro-OMeTAD. Consequently, FACsPbI₃ PSCs with CoFAc modification display a champion power conversion efficiency (PCE) of 24.64% with a charming open-circuit voltage (V _OC) of 1.191 V, which is the record V _OC among all the reported organic-inorganic hybrid PSCs with TiO₂ as electron transport layer. Furthermore, CoFAc-modified devices exhibit an outstanding long-term stability, which can maintain 95% of their initial PCEs after exposure to ambient atmosphere for 1500 h without any encapsulation.

A facile approach of introducing pre-located and ligand-optimized Ag nanoparticles to assist the formation of high-quality ultrathin (≈7 nm) evaporated Ag films is demonstrated for transparent top electrodes. Devices employing these films exhibit remarkable electrical and optical properties, and excellent interfacial contact with the lower layer. As prepared semi-transparent organic solar cells achieve a power conversion efficiency of 12.80% with high light utilization efficiency of 4.422%.

Abstract

Semi-transparent organic solar cells (STOSCs) have great potential in power-generating windows for building facades and automobiles. At present, the evaporated metal thin film is widely used as the transparent top electrode in STOSCs owing to its relatively high conductivity. However, its transmittance in the visible range is sacrificed for fulfilling the thickness requirement of the electrical percolation threshold. Herein, a facile approach of introducing pre-located Ag nanoparticles (NPs) with an optimized amount of ligands is demonstrated to promote the high-quality and ultrathin evaporated Ag film formation for high-performance transparent electrodes beyond that of merely evaporated electrodes. With the pre-located and ligand-optimized Ag NPs, the growth of evaporated Ag clusters can be guided to form high-quality transparent electrode. Equally important, the approach also reduces the mis-stacking defects of the electron transport layer and thus favors the carrier transportation/extraction to the electrode. By using these Ag NPs/7 nm Ag with a sheet resistance less than 15 Ω sq⁻¹ and average transmittance of 59.30% in the visible region as the main structure in the top electrode, a PM6:L8-BO based STOSC achieves light utilization efficiency of 4.422% with a remarkable power conversion efficiency of 12.80%. This work provides a facile strategy to not only realize high-quality and transparent ultrathin electrode with detailed understanding, but also to promote the practical applications of semi-transparent photonic devices.

An enhanced crystallinity and a more suitable phase separation of donor and acceptor is finely controlled by optimizing the processing solvents in sequential blade coated organic solar cells, resulting in a superior performance of 17.23%.

Abstract

Sequential deposition of the active layer in organic solar cells (OSCs) is favorable to circumvent the existing drawbacks associated with controlling the microstructure in bulk-heterojunction (BHJ) device fabrication. However, how the processing solvents impact on the morphology during sequential deposition processes is still poorly understood. Herein, high-efficiency OSCs are fabricated by a sequential blade coating (SBC) through optimization of the morphology evolution process induced by processing solvents. It is demonstrated that the device performance is highly dependent on the processing solvent of the upper layer. In situ morphology characterizations reveal that an obvious liquid–solid phase separation can be identified during the chlorobenzene processing of the D18 layer, corresponding to larger phase separation. During chloroform (CF) processing of the D18 layer, a proper aggregation rate of Y6 and favorable intermixing of lower and upper layers results in the enhanced crystallinity of the acceptor. This facilitates efficient exciton dissociation and charge transport with an inhibited charge recombination in the D18/CF-based devices, contributing to a superior performance of 17.23%. These results highlight the importance of the processing solvent for the upper layer in the SBC strategy and suggest the great potential of achieving optimized morphology and high-efficiency OSCs using the SBC strategy.

A new pyridine-based polymer hole-transporting material is developed through backbone engineering strategy to simultaneously modulate the interface and crystallinity of inverted perovskite solar cells, resulting in a remarkable power conversion efficiency of 24.89% (certified 24.50%) with outstanding stability.

Abstract

The interface and crystallinity of perovskite films play a decisive role in determining the device performance, which is significantly influenced by the bottom hole-transporting material (HTM) of inverted perovskite solar cells (PVSCs). Herein, a simple design strategy of polymer HTMs is reported, which can modulate the wettability and promote the anchoring by introducing pyridine units into the polyarylamine backbone, so as to realize efficient and stable inverted PVSCs. The HTM properties can be effectively modified by varying the linkage sites of pyridine units, and 3,5-linked PTAA-P1 particularly demonstrates a more regulated molecular configuration for interacting with perovskites, leading to highly crystalline perovskite films with uniform back contact and reduced defect density. Dopant-free PTAA-P1-based inverted PVSCs have realized remarkable efficiencies of 24.89% (certified value: 24.50%) for small-area (0.08 cm²) as well as 23.12% for large-area (1 cm²) devices. Moreover, the unencapsulated device maintains over 93% of its initial efficiency after 800 h of maximum power point tracking under simulated AM 1.5G illumination.

A fluorinated phenmethylammonium salt is designed and synthesized to simultaneously passivate the perovskite top surface and the buried interface. A stabilized efficiency of 18.0% is achieved for perovskite solar modules with a 10.0 cm² active area.

Abstract

Surface passivation with organic halide salts is a powerful strategy to enhance the performance of perovskite solar cells. However, the inevitable formed in-plane favored two-dimensional perovskite layers with low carrier mobility and high binding energy inhibit the interfacial charge transfer within the device. Herein, a bulky fluorinated phenmethylammonium salt is designed and synthesized to passivate the perovskite film without forming 2D perovskites. A strong interaction which is induced by an electron donation from passivation agent to perovskite not only reduces the defects at the top surface of the perovskite, but also suppresses the recombination reaction at the buried surface due to a permeation of the organic halide salt. Moreover, the results of time resolved photoluminescence and confocal microscopy images suggest that the interfacial charge transfer speed and uniformity are enhanced. As a result, the efficiency of a small-area device increases from 20.7 ± 0.9% to 22.8 ± 0.4% (aperture: 0.16 cm²). Moreover, a stabilized efficiency of 18.0% (aperture: 10.0 cm²) is achieved for larger-area modules with 6-series connected sub-cells. Equally important, the non-encapsulated modules show significantly improved stability at ambient conditions (ISOS-D-1). These significant improvements provided by a simple and reproducible procedure can be readily adopted in other types of devices.

Nickel acetate (NiAc₂) is introduced into SnO₂/perovskite interface as a bidirectional modifier to passivate oxygen vacancies of SnO₂, optimize the energy level alignment of SnO₂/perovskite interface, as well as improve the crystal quality of perovskite, which significantly boost the power conversion efficiency of planar SnO₂-based perovskite solar cells to 23.02% with an ultrahigh open-circuit voltage of 1.17 V.

Planar n–i–p perovskite solar cells (PSCs) based on a SnO₂ electron transport layer dominate the certified high-efficiency devices. However, the defects located at the SnO₂/perovskite interface (i.e., buried interface) or inside the perovskite films impede the further improvement of power conversion efficiency (PCE). Herein, nickel acetate (NiAc₂) is introduced on buried interface as a bidirectional modifier to improve electron extraction of SnO₂ and the crystal growth of perovskite for the first time. First, NiAc₂ is chemically anchored on SnO₂ to passivate oxygen vacancies, increase conductivity, and optimize the energy level alignment of the buried interface. Second, the porous morphology of PbI₂ film deposited on NiAc₂-modified SnO₂ endows more sufficient permeation and reaction of organic amine salts (formamidinium iodide [FAI] and methylammonium iodide [MAI]), forming high-quality perovskite film with reduced PbI₂ residues. Meanwhile, NiI₂ and MAAc/FAAc may be produced via in situ reaction between NiAc₂ and organic amine salts, which serve as interface modifier and crystallization regulator to further reduce defects located at the buried interface or inside the perovskite film, respectively. Consequently, an improved PCE of 23.02% for SnO₂-based PSCs with an ultrahigh open-circuit voltage of 1.17 V is obtained. In addition, long-term storage and light stability of the optimized PSCs are improved.

The donor–acceptor interface regulation is essential to reduce trap density in the active layer and, thus, the trap-assisted charge recombination under indoor light illumination, leading to improved open circuit voltage. By tuning the interfaces, organic solar cells prepared in bilayer structure outperform their counterparts with bulk heterojunction active layers due to the lower energetic disorder and trap density.

Organic solar cells (OSCs) are promising candidates for powering the Internet of Things and off-grid devices due to the rapid improvement in power conversion efficiency under indoor light. However, the reported indoor devices are often taken straightforwardly from the champion solar cells under AM1.5 G irradiance without further optimization or more target design, which may underestimate their performance due to trap-assisted charge recombination caused by discrepancies in incident light spectrum and intensity. Herein, It is identified that regulation of donor–acceptor interfaces is critical for reducing trap density in the active layer and thus improving the performance of indoor OSCs. By investigating bulk heterojunction and bilayer devices composed of PM6 and ITIC or ITIC-2 F, reduced trap density is demonstrated by mitigation of the structural disorder of the active layer, leading to improved open-circuit voltage. Additionally, the trap depth has a negligible effect on the device's performance with indoor light illumination. The results establish the correlations between donor–acceptor interfaces and charge recombination losses in bulk heterojunction and bilayer OSCs under indoor light, providing novel optimization guidelines for high-performing indoor OSCs.

Herein, we introduce l- and d-cysteine into carbon-based printable mesoscopic solar cells as additives. Due to the enhancement of the negative surface electrostatic potential around carboxyl group with chiral molecular environment favoring intramolecular charge transfer with l-cysteine strengthen the coordination to under-coordinated Pb²⁺ (halide vacancy) defects, a 17.41% power conversion efficiency was obtained compared with 15.12% of d-cysteine.

Amino acid, with amino, carboxyl, and other functional groups in one molecule, is proposed as an effective multisite passivator for perovskite solar cells (PSCs). However, the chirality-induced difference in photovoltaic properties of PSCs caused by subtle changes of the molecular environment between enantiomers of the amino acid has received almost no attention. Herein, for the first time, l- and d-cysteine are introduced into carbon-based fully printable mesoscopic PSCs as additives and 17.41 and 15.12% of power conversion efficiency are obtained, respectively. The essential causes of the differences in photoelectric conversion performances are deeply explored within a density-functional theory (DFT) framework and relative photophysical characterization. DFT reveals that the enhancement of negative surface electrostatic potential around the carboxyl group is due to the chiral molecular environment favoring intramolecular charge transfer with l-cysteine, strengthening the coordination to undercoordinated Pb²⁺ (halide vacancy) defects. In addition, the advantages of the chiral environment of l-cysteine are also reflected in the inhibition of nonradiative recombination, perovskite crystallization, stability, and light capture, etc. It opens up a novel research pathway extending passivation mechanism from functional groups to the molecular environment.

This article reveals that quasi-2D bottom passivation improves inverted perovskite solar cell device performance. The vacuum-assisted blade coating perovskite solar cells fabricated in the ambient environment using NiO _x as hole transport layer achieve an efficiency of 20.7%, paving the way for developing highly efficient, large-area, low-cost, and stable perovskite solar cells.

Metal halide perovskite solar cells (PSCs) attract an enormous attention because of their high power conversion efficiency (PCE) and low fabrication cost. However, their commercialization is limited by fabricating highly efficient large-area solar cells. Controlling the morphology and crystallization of perovskite for large-area fabrication is difficult but important. Herein, a vacuum-assisted approach is developed to obtain mirror-like, pinhole-free, highly crystalline, and uniform blade-coated perovskite films, without the use of antisolvent and air knife. This method can be a universal approach for various perovskite compositions. Meanwhile, the phenethylammonium iodide passivation effect at the top and bottom interfaces of perovskite layer based on FTO/NiO _x /perovskite/C₆₀/BCP/Cu inverted p-i-n structure is systematically investigated. The optimized device fabricated by blade coating under an ambient environment exhibits the champion PCE of 20.7% and is among the top few records of blade coating inverted structure based on NiO _x hole transport layer. The encapsulated device retains 97% of its maximum efficiency under open-circuit condition after 1000 h of photostability test in an ambient environment at room temperature with a relative humidity of 40–60%. Herein, low-cost, easy, and reproducible strategies to fabricate efficient and stable blade-coated PSCs are demonstrated.

Publication date: March 2023

Source: Nano Energy, Volume 107

Author(s): Chintam Hanmandlu, Rohan Paste, Hsinhan Tsai, Shyam Narayan Singh Yadav, Kuan-Wen Lai, Yen-Yu Wang, Chandra Shekar Gantepogu, Chen-Hung Hou, Jing-Jong Shyue, Yu-Jung Lu, Tushar Sanjay Jadhav, Jian-Ming Liao, Hsien-Hsin Chou, Hui Qi Wong, Ta-Jen Yen, Chao-Sung Lai, Dibyajyoti Ghosh, Sergei Tretiak, Hung-Ju Yen, Chih-Wei Chu

Publication date: March 2023

Source: Nano Energy, Volume 107

Author(s): Yuting Chen, Qi Wang, Weijian Tang, Wuke Qiu, Yihui Wu, Qiang Peng

Publication date: March 2023

Source: Nano Energy, Volume 107

Author(s): Chengcheng Xie, Chengyi Xiao, Jie Fang, Chaowei Zhao, Weiwei Li

A polymer donor PBOF with a donor–donor-conjugated skeleton and an ultrawide bandgap up to 2.20 eV is designed for colorful semitransparent organic solar cells (ST-OSCs). The blend of PBOF and near-infrared electron acceptor reduces the absorption overlap with the photopic response spectrum of the human eye and delivers colorful ST-OSCs by adjusting the donor/acceptor ratio in the active layer.

Abstract

Semitransparent organic solar cells (ST-OSCs) have attracted increasing attention due to their promising prospect in building-integrated photovoltaics. Generally, efficient ST-OSCs with good average visible transmittance (AVT) can be realized by developing active layer materials with light absorption far from the visible light range. Herein, the development of ultrawide bandgap polymer donors with near-ultraviolet absorption, paired with near-infrared acceptors, is proposed to achieve high-performance ST-OSCs. The key points for the design of ultrawide bandgap polymers include constructing donor–donor type conjugated skeleton, suppressing the quinoidal resonance effect, and minimizing the twist of conjugated skeleton via noncovalent conformational locks. As a proof of concept, a polymer named PBOF with an optical bandgap of 2.20 eV is synthesized, which exhibited largely reduced overlap with the human eye photopic response spectrum and afforded a power conversion efficiency (PCE) of 16.40% in opaque device. As a result, ST-OSCs with a PCE over 10% and an AVT over 30% are achieved without optical modulation. Moreover, colorful ST-OSCs with visual aesthetics can be achieved by tuning the donor/acceptor weight ratio in active layer benefiting from the ultrawide bandgap nature of PBOF. This study demonstrates the great potential of ultrawide bandgap polymers for efficient colorful ST-OSCs.

High-performance CsPbI₂Br inorganic perovskite solar cells (IPSC) with enhanced phase stability are demonstrated. A nonstoichiometric compositional engineering method is developed to quickly obtain high-quality perovskite films with micrometer-scale crystal grains. Moreover, a post-cation exchange method is demonstrated to further enhance the efficiency and phase stability of CsPbI₂Br IPSCs, and enables a record efficiency of 17.80%.

Abstract

The inorganic perovskite solar cells (IPSC) are promising in the context of simultaneously delivering high efficiency and good stability. Developing a high-performance and larger band gap IPSC is particularly in demand for commercialization due to their suitability to match with the prevailing silicon solar cells for tandem devices, while this is hindered by the poor morphology and phase stability of inorganic perovskite films. To address this issue, this work develops a combined method of nonstoichiometric composition and post-cation exchange to improve the morphology and phase stability of the CsPbI₂Br IPSCs, and achieves a record efficiency of 17.80%. This work finds that excessive PbI₂ regulates the CsPbI₂Br film crystallization, and thus, a high-quality perovskite film with enlarged grains is obtained. Further depositing the formamidinium iodide on top of the CsPbI₂Br perovskite induces cation exchange during the post-annealing process, which increases the phase stability of the perovskite film and significantly improves the device efficiency and stability. Therefore, this work provides an avenue toward high-performance IPSCs, via the nonstoichiometric and ion exchange method.

Fabricating efficient air-processed organic solar cells (OSCs) using green-solvents and the simplest possible photoactive material-combinations is vital for their commercial viability, since roll-to-roll-processing infrastructure is designed to operate in ambient-conditions. In this article, air-processed OSCs are reported that show enhanced crystallinity and long-lived charge-separated states, resulting in 17.38% power conversion efficiency in a two-component and green-solvent-based OSC-system which is higher than its glove-box processed counterpart.

Abstract

Power conversion efficiencies (PCEs) of glove-box (GB) processed, two-component, single-junction organic solar cells (OSCs) have recently exceeded 18%. However, their mass-scale manufacture using roll-to-roll (R2R) coating techniques is impracticable if they must be fabricated in an air-free environment. From a commercialization perspective, efficient air-processed OSCs are of much greater interest than GB-processed devices since the vast majority of R2R-manufacturing infrastructure is designed to operate in the air. Herein, it is reported that controlling the crystallinity of non-fullerene acceptors plays a key role in determining the properties of blend films. Notably, Y6-hu (a Y6-derivative) is shown to exhibits a higher degree of crystallinity when processed in air. Air-processed OSCs show an outstanding PCE of 17.38%, which, to the best of the authors’ knowledge, is the highest PCE yet reported for two-component-based OSCs processed in air using halogen-free solvents. Moreover, opaque large-area OSC sub-modules with PCEs of 12.44%, and red-green-blue colored semi-transparent OSC sub-modules with PCEs of >10% are demonstrated. By understanding how morphological features relate to the charge-generation dynamics of air-processed OSCs, a new window is opened for the fabrication of efficient and stable air-processable organic electronics.

A hot-air-assisted ambient fabrication technique is introduced to prepare 2D layered perovskite films for efficient and stable solar cells. This method is material-saving, humidity-insensitive, large-area-applicable, and adaptable for different 2D perovskites. High-quality 2D perovskite films are obtained with good crystallinity, preferable orientation, and desirable morphology.

Abstract

2D layered perovskites (LPs) have shown great potential to deliver high-performance photovoltaic devices with long-term stability. Despite many signs of progress being made in film quality and device performance, LP films are mainly processed in strict conditions and through non-scalable techniques. Here, the hot-air-assisted ambient fabrication technique is introduced to prepare LP films for efficient and stable solar cells. The high-quality LP films with good crystallinity, preferable orientation and desirable morphology are obtained by balancing the crystal nucleation and growth processes. Employing the synchrotron-based in situ grazing-incidence X-ray diffraction technique, hot air induces the solidification of solutes and forms an intermediate at the air–liquid interface, which transforms into 3D-like perovskite, followed by the growth of the 2D species toward the substrate. The optimal LP film delivers a device power conversion efficiency of 16.36%, the best value for the LP-based solar cells prepared by the non-spin-coating techniques. The solar cell performance is insensitive to the film processing humidity and the device size is upscalable, which promises real-world deployment of LP-based optoelectronic devices.

A ferroelectric two-dimensional (2D) perovskite has been designed based on a pyridine ring as the organic interlayer. Incorporation of the ferroelectric 2D material into 3D perovskite induces an increased built-in electric field and optimized perovskite crystallization, delivering an exceptional efficiency over 23 % for flexible perovskite solar cells.

Abstract

Despite the great progress of flexible perovskite solar cells (f-PSCs), it still faces several challenges during the homogeneous fabrication of high-quality perovskite thin films, and overcoming the insufficient exciton dissociation. To the ends, we rationally design the ferroelectric two-dimensional (2D) perovskite based on pyridine heterocyclic ring as the organic interlayer. We uncover that incorporation of the ferroelectric 2D material into 3D perovskite induces an increased built-in electric field (BEF), which enhances the exciton dissociation efficiency in the device. Moreover, the 2D seeds could assist the 3D crystallization by forming more homogeneous and highly-oriented perovskite crystals. As a result, an impressive power conversion efficiency (PCE) over 23 % has been achieved by the f-PSCs with outstanding ambient stability. Moreover, the piezo/ferroelectric 2D perovskite intrigues a decreased hole transport barriers at the ITO/perovskite interface under tensile stress, which opens new possibilities for developing highly-efficient f-PSCs.

Publication date: 18 January 2023

Source: Joule, Volume 7, Issue 1

Author(s): Essa A. Alharbi, Anurag Krishna, Nikolaos Lempesis, Mathias Dankl, Irea Mosquera-Lois, Michael A. Hope, Thomas P. Baumeler, George Kakavelakis, Aditya Mishra, Felix T. Eickemeyer, Olivier Ouellette, Thanyarat Chawanpunyawat, Anders Hagfeldt, Shaik M. Zakeeruddin, Lyndon Emsley, Lukas Pfeifer, Ursula Roethlisberger, Michael Grätzel

A highly efficient inherent linearly polarized light-emitting diode (LP-LED) is constructed based on 2,6-diphenylanthracene (DPA) single crystals (SCs) with an in-plane anisotropic property. The LP-LED exhibits excellent device performance with external quantum efficiency (EQE) of 3.38% and degree of polarization (DOP) up to 0.74. Further, an interchip polarized optical communication system is demonstrated based on the LP-LED.

Abstract

Small-molecule organic single crystals (SCs) with an inherent in-plane anisotropic nature enable direct linearly polarized light emission without the need for spatially separated polarizers and complex optical structures. However, the device performance is severely restricted by the starvation of appropriate SC emitters and the difficulty in the construction of efficient SC electroluminescence (EL) devices, leading to a low external quantum efficiency (EQE) of usually smaller than 1.5%. Here, highly efficient inherent linearly polarized light-emitting diodes (LP-LEDs) are demonstrated by exploiting 2,6-diphenylanthracene (DPA) SCs as intrinsically polarized emitters. The LP-LEDs exhibit a 2.5-fold enhanced maximum EQE of 3.38%, which approaches the theoretical limit for the DPA SC-based EL device and is the highest among organic SC-based LEDs reported thus far. More importantly, a high degree of polarization (DOP) up to 0.74 is achieved for the intrinsically polarized EL emission of the DPA SC-based LP-LEDs. By leveraging the highly efficient LP-LED, an interchip polarized optical communication system consisting of organic SCs is demonstrated for the first time. This work creates a solid foundation for the exploitation of a vast new library of small-molecule organic SCs for LP-LEDs and carries broad implications for polarized optics and relevant optoelectronic devices.

Nature Energy, Published online: 24 December 2022; doi:10.1038/s41560-022-01172-w