Weiwei Li

Beijing University of Chemical Technology | buct · College of Materials Science and Engineering (SMSE)

Organic solar cells (OSCs) with the conventional configuration usually use polyethylenedioxythiophene:polystyrene sulfonate (PEDOT:PSS) as the hole‐transporting layer (HTL); however, its acidity tends to affect the performance and long‐term stability of the devices. Therefore, replacing PEDOT:PSS with other more stable HTLs is essential for realizi...

The incorporation of insulating polymers into conjugated polymers has been widely explored as a strategy to improve mechanical properties of flexible organic electronics. However, phase separation due to the immiscibility of these polymers has limited their effectiveness. In this study, we report the discovery of a novel non‐covalent interaction th...

The incorporation of insulating polymers into conjugated polymers has been widely explored as a strategy to improve mechanical properties of flexible organic electronics. However, phase separation due to the immiscibility of these polymers has limited their effectiveness. In this study, we report the discovery of a novel non‐covalent interaction th...

The invention of near-infrared pedant-based double-cable conjugated polymers has demonstrated remarkable efficacy in single-component organic solar cells (SCOSCs). This work focuses on the innovative double-cable conjugated polymers aimed at attaining good absorption and suitable energy levels. Specifically, in the aromatic side units, the electron...

A cross-linking strategy can result in a three-dimensional network of interconnected chains for the copolymers, thereby improving their mechanical performance. In this work, a series of cross-linked conjugated copolymers, named PC2, PC5, and PC8, constructed with different ratios of monomers are designed and synthesized. For comparison, a random li...

The electron transport layer (ETL) is a critical component in achieving high device performance and stability in organic solar cells. Conjugated polyelectrolytes (CPEs) have become an attractive alternative due to film‐forming properties and ease of preparation. However, p‐type CPEs generally exhibit poor charge mobility and conductivity, incorpora...

Herein, three double-cable conjugated polymers are developed for indoor single-component organic solar cells (SCOSCs). The new double-cable conjugated polymers contain pendent nonfused electron acceptors with A-π-D-π-A configuration, in which group A uses 1H-indene-1,3(2H)-dione (ID) as an electron-withdrawing end group. The innovative design enabl...

Double‐cable conjugated polymers with pendent electron acceptors, including fullerene, rylene diimides and non‐fused acceptors, have been developed for application in single‐component organic solar cells (SCOSCs) with efficiencies approaching 10%. In this work, Y‐series electron acceptors have been firstly incorporated into double‐cable polymers in...

By combining stable radical tetramethylpiperidine nitrogen oxide(TEMPO) as end groups and perylene bisimide(PBI) as the core, a small molecular cathode interlayer(CIL) (PBI-TEMPO) was synthesized. Detailed physical-chemical characterizations indicate that PBI-TEMPO can form smooth film, owns low unoccupied molecular orbital(LUMO) level of −3.67 eV...

Polymerized small-molecule acceptors (PSMAs) have made significant progress as the application in all-polymer solar cells (all-PSCs). Most PSMAs are constructed by near-infrared fused-ring electron acceptors via Stille polymerization, such as Y-series acceptors. However, very limited non-fused electron acceptors with simplified synthetic complexity...

Near-infrared electron acceptors for organic solar cells (OSCs) mostly contain electron-withdrawing 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (IC) end groups, which can be modified by but limited to phenyl, thienyl, and naphthyl units with halogenated, methyl, and methyloxy substitution. In this work, we employed an imide-containing uni...

In this work, the hierarchical surface reactivity of a kind of Ti-oxo cluster (TOC) with robust cyclic structure, CTOC, supported by multiple surface ligands, has been initially established. By this method, a series of aromatics (i.e., benzoate for CTOC-Ph, 4-methylbenzoate for CTOC-PhMe and 4-cyanobenzoate for CTOC-PhCN) substituted CTOC-Ars, with...

Donor polymers based on benzothiadiazole have shown a higher power conversion efficiency of 15.5% in organic solar cells.

Correction for ‘Effects of alkyl chains of benzothiadiazole-based conjugated polymers on the photovoltaic performance of non-fullerene organic solar cells’ by Chao Wang et al. , Polym. Chem. , 2023, 14 , 616–622, https://doi.org/10.1039/D2PY01473D.

In this work, a perylene bisimides (PBIs) based electrolyte PDIN-TEMPO pendent with a stable radical 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) has been synthesized and used as cathode interlayer (CIL) in organic solar...

Double-cable conjugated polymers contain electron-donating (D) backbones and electron-accepting (A) side units, in which the nanophase separation of the donor and acceptor segments is a crucial factor to determine the...

Single-component organic solar cells (SCOSCs) use a single polymer in the photoactive layer, which is different from bulk-heterojunction organic solar cells with physically-mixed electron donor and acceptor as the photoactive layer. In this article, we summarize the advances in double-cable conjugated polymers. Now the power conversion efficiencies...

As a versatile class of semiconductors, diketopyrrolopyrrole (DPP)-based conjugated polymers are well suited for applications of next-generation plastic electronics because of their excellent and tunable optoelectronic properties via a rational design of chemical structures. However, it remains a challenge to unravel and eventually influence the co...

In this work, an inorganic semiconductor SnOx has grown on the surface of silver nanowires (AgNWs) to form core/shell electrodes, which was successfully applied into flexible indoor organic solar cells (OSCs). Based on the redox reaction between Sn²⁺ and Ag⁺, the pristine AgNWs thin films were treated by SnCl2 in an aqueous solution, so that SnOx w...

Poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a widely used hole transporting layer (HTL) in organic solar cells (OSCs), but its acidity severely reduces the stability of devices. Until now, very few HTLs were developed to replace PEDOT:PSS toward stable and high‐performance OSCs. Herein, a new cobalt‐lanthanum (Co‐La) inor...

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a widely used hole transporting layer (HTL) in organic solar cells (OSCs), but its acidity severely reduces the stability of devices. Until now, very few HTLs were developed to replace PEDOT:PSS toward stable and high-performance OSCs. Herein, a new cobalt-lanthanum (Co-La) inor...

In this work, we have introduced single/double-sided N-annulated perylene bisimide (PBI) with deep energy levels into double-cable polymers with poly[1-(5-(4,8-bis(4-chloro-5-(2-ethylhexyl)thiophen-2-yl)-6-methylbenzo[1,2-b:4,5-b']dithiophen-2-yl)thiophen-2-yl)-5,7-bis(2-ethylhexyl)-3-(5-methylthiophen-2-yl)-4H,8H-benzo[1,2-c:4,5-c']dithiophene-4,8...

The molecular orientations of conjugated materials on the substrate mainly include edge‐on, face‐on, and end‐on. Edge‐on and face‐on orientations have been widely observed, while end‐on orientation has been rarely reported. Since in organic solar cells (OSCs) charge transport is along the vertical direction, end‐on orientation with conjugated backb...

The recently emerged double-cable conjugated polymers have come into focus due to their significantly improved power conversion efficiencies (PCEs) in single-component organic solar cells (SCOSCs). In this work, the effect of chlorination in double-cable conjugated polymers with linear benzodithiophene backbone and pendant perylene bisimide on the...

Cathode interlayer (CIL) is responsible for electron extraction and hole blocking between the photoactive layer and the electrode. Since the excellent inorganic CIL materials, such as ZnO, TiO2 and SnO2, are difficult to be applied in high performance non-fullerene organic solar cells with conventional structures, novel organic-inorganic hybrid mat...

High power conversion efficiency (PCE), operational stability and low cost are essential for the commercial applications of ultraflexible organic solar cells (OSCs), but still challenging. Here, a high-performance polyimide (PI)/ZnO composite (PI-ZnO) was prepared via introducing ZnO nanocrystals to an elaborately designed PI with both hydrogen bon...

Organic solar cells (OSCs) have witnessed great progress over past years. Various breakthroughs, such as record power conversion efficiencies of single junction or tandem OSCs, high performing flexible devices and...

High-molecular-weight conjugated polymers exhibit excellent mechanical properties due to long-chain entanglement, but it is challenging to increase molecular weight since conjugated polymers with rigid backbones show low solubility and tend to be precipitated during polymerization. In this work, we have successfully obtained high-molecular-weight p...

Double‐cable conjugated polymers with near‐infrared (NIR) electron acceptors are synthesized for use in single‐component organic solar cells (SCOSCs). Through the development of a judicious synthetic pathway, the highly sensitive nature of the 2‐(3‐oxo‐2,3‐dihydroinden‐1‐ylidene)malononitrile (IC)‐based electron acceptors in basic and protonic solv...

Double‐cable conjugated polymers with near‐infrared (NIR) electron acceptors are synthesized for use in single‐component organic solar cells (SCOSCs). Through the development of a judicious synthetic pathway, the highly sensitive nature of the 2‐(3‐oxo‐2,3‐dihydroinden‐1‐ylidene)malononitrile (IC)‐based electron acceptors in basic and protonic solv...

Ultrathin organic solar cells (OSCs) with both high power conversion efficiency (PCE) and operational stability are of great significance for the industrial applications but still challenging. Here, we synthesized a polyimide (PI) substrate for high‐performance and stable ultrathin OSCs, which was physically crosslinked via strong hydrogen bonds (d...

The alkyl chains as linkers in double-cable conjugated polymers play an important role in the solubility, packing motif, morphology, and voltage loss in single-component organic solar cells (SCOSCs). In this work, we incorporate alkyl linkers with lengths from hexyl (C6H12) to hexadecyl (C16H32) into naphthalene diimide-based double-cable conjugate...

Organic solar cells (OSCs), which are widely regarded as the promising power source for next‐generation electronics, have potential applications in architecture‐integrated photovoltaics, the internet of things (IoTs), self‐powered wearable sensors, electronic textiles, and implantable sensors due to their instinct nature of flexibility and high mas...

Single‐component organic solar cell (SCOSC) containing only one material in the active layer is one type of organic solar cells. However, it is difficult to integrate donor (D) and acceptor (A) part into one material to satisfy the absorption of sunlight, charge generation, and transport simultaneously. As a result, the best power conversion effici...

Double-cable conjugated polymers have shown promising application in single-component organic solar cells, in which the microstructures of donor/acceptor segments have a significant impact on their photovoltaic performance. Double-cable polymers always use alternating copolymers design, in which the pendent acceptor side units have the fixed conten...

Although the power conversion efficiencies (PCEs) of bulk heterojunction (BHJ) organic solar cells (OSCs) continue increasing toward the 20% milestone, important factors for industrial application are mostly neglected, such as photostability and cost potential. Single-component OSCs (SCOSCs) employing materials with chemically bonded donor and acce...

With the rapid development of flexible optoelectronic devices, recyclability is highly desirable for alleviating resource waste and environmental pollution, but remains challenging. Here, a fully closed-loop recyclable crosslinked polyimide (RCPI) was fabricated via carboxyl ligand exchange between the CPI with pendent carboxyl groups and the cycli...

In this work, the “functionalization-polymerization” (FP) method has been used to construct fullerene-contained double-cable conjugated polymers with “donor-acceptor” backbones. It was realized via synthesizing a fullerene-contained monomer and performing Stille polymerization. With this method, a series of double-cable conjugated polymers with dif...

Organic solar cells (OSCs) have gained a rapid development in the past two decades and the power conversion efficiency (PCE) of single-junction OSC has recently approached 20%. The novel materials and device engineering are two key factors of this evolution. In this review, the device engineering, including morphology characterization and optimizat...

Photomultiplication-type organic photodetectors (PM-OPDs) have attracted enormous interest owing to their high sensitivity toward weak light and, especially, due to their excellent parasitic stability when using a single polymer as the active layer. Herein, three different polymers, DCP1-3, were synthesized with different amounts of PC61BM pendants...

Near-infrared electron acceptors play an important role in organic solar cells (OSCs), in which they can usually be divided into fused and non-fused electron acceptors. In this work, we reported the first naphthobistriazole (NT) based non-fused electron acceptors for OSCs. The new acceptors contain NT unit as the central core, cyclopentadithiophene...

Two kinds of small molecular dyads (SMDs) based on trithiophene-benzodithiophene-rhodanine (DR3TBDT) main backbone and PBI termini, named SMD2-C6 and SMD2-C12, were designed by tuning the length of alkyl linkers (C6H12 and C12H24). The effect of the alkyl linkers length on the photovoltaic performance of the two SMDs have been systematically studie...

Indoor photovoltaic is one of the most important applications of organic solar cells (OSCs). As different from AM1.5G sunlight with broad spectra from visible to near-infrared region, the spectra of indoor light are usually located at the visible region. Therefore, a special material design for the photoactive layer to meet the requirement of indoo...

Silver nanowires (AgNWs) are the most important transparent electrodes for flexible optoelectronics. Their high aspect ratio and metallic nature make them tend to aggregate and yield inhomogeneous conducting films, which...

During past several years, the photovoltaic performances of organic solar cells (OSCs) have achieved rapid progress with power conversion efficiencies (PCEs) over 18%, demonstrating a great practical application prospect. The development of material science including conjugated polymer donors, oligomer-like organic molecule donors, fused and nonfus...

Single-component organic solar cells (SCOSCs) have witnessed great improvement during the last few years with the champion efficiency jumping from the previous 2–3% to currently 6–11% for the representative material classes. However, the photophysics in many of these materials has not been sufficiently investigated, lacking essential information re...

Cathode interlayer (CILs) play important roles in promoting high-performance organic solar cells, which are usually fabricated in multi-layer structures. Among the commonly used CILs, metal oxides, such as ZnO, TiO2 and SnO2, display suitable work function and high conductivity. However, they usually need to be processed under high temperature and...

The high voltage losses ( $${V}_{{loss}}$$ V l o s s ), originating from inevitable electron-phonon coupling in organic materials, limit the power conversion efficiency of organic solar cells to lower values than that of inorganic or perovskite solar cells. In this work, we demonstrate that this $${V}_{{loss}}$$ V l o s s can in fact be suppressed...

The adding of insulating polymers into conjugated polymers is an efficient strategy to tailor their mechanical properties for flexible organic electronics. In this work, we selected two insulating polymers as additives into high‐performance photoactive layers to study the mechanical and photovoltaic properties in organic solar cells (OSCs). The ins...

The rapid developments of nonfullerene small molecular acceptors (NF-SMAs) have dominated the improvement of photoelectron conversion efficiencies (PCEs) for organic solar cells. Light absorption reaching the near-infrared (NIR) region is the primary feature for NF-SMAs compared with fullerene derivatives, enabling their enhanced efficiencies in so...

Zinc oxide nanoparticles (ZnO NPs) are among the well-known electron transporting layers (ETLs) in flexible electronics, especially in organic solar cells (OSCs). This is due to their high mobility and transparency, annealing-free and solution-processable features, large-area fabrication technique compatibility,etc.This review summarizes the synthe...

Exciton dissociation between donor and acceptor is the decisive process to determine the photovoltaic performance of organic solar cells (OSCs). The rather fast dynamics of photo‐induced charge generation in well‐optimized bulk heterojunction (BHJ) composites complicate the quantitative analysis of the charge generation efficiency for donor and acc...

Highly‐crystalline conjugated polymers are important for microstructure analysis and charge transport in organic electronics. In this work, we have developed a series of highly‐crystalline double‐cable conjugated polymers for application in single‐component organic solar cells (SCOSCs). These polymers contain conjugated backbones as electron donor...

Highly‐crystalline conjugated polymers are important for microstructure analysis and charge transport in organic electronics. In this work, we have developed a series of highly‐crystalline double‐cable conjugated polymers for application in single‐component organic solar cells (SCOSCs). These polymers contain conjugated backbones as electron donor...

Organic solar cells (OSCs) that converted sunlight into electricity have obtained numerous progress in the past two decades. With the effort of developing new conjugated materials, the power conversion efficiencies (PCEs) of OSCs have realized over 18%, which is comparable with other types of solar cells. These great achievements enable OSCs to arr...

Owing to the advantages of being lightweight and compatible with surfaces with different deformations, flexible organic solar cells (OSCs) have broad scopes of applications, including wearable electronics and portable devices. Most flexible OSCs focus on the two‐component bulk‐heterojunction (BHJ) photo‐active layers, but they usually suffer from d...

Single-component organic solar cells (SCOSCs) with high stability and simplified fabrication process are supposed to accelerate the commercialization of organic photovoltaics. However, the types of photo-active materials and photovoltaic performance of SCOSCs are still far lagging behind the bulk-heterojunction type organic solar cells (BHJ OSCs)....

In this work, we introduced a fullerene acceptor (PC71BM) into the binary photo-active layer based on a polymer donor (PM6) and a non-fullerene small molecular acceptor (BTP-BO-4Cl), and as a consequence, the ternary organic solar cells realized a high-power conversion efficiency of 17.39% compared to 16.65% in binary solar cells. The performance e...