Weiwei Li

• Doctor of Philosophy
• Professor at Beijing University of Chemical Technology

Fullerene derivatives are widely employed as efficient electron-transporting layers (ETLs) in p-i-n perovskite photovoltaics but face challenges in mitigating interfacial recombination losses and ensuring stable film morphology. Non-fullerene acceptors (NFAs), commonly utilized in organic photovoltaics, present a promising alternative to fullerene-...

A novel series of alkynyl‐linked oligomerized electron acceptors have been synthesized via Sonogashira coupling. The alkynyl linkages can enhance molecular planarity and aggregation, suppress electron‐phonon coupling, and reduce non‐radiative losses. Binary organic solar cells (OSCs) achieved an efficiency of 17.90%, with a non‐radiative loss of 0....

Metal–organic complexes have demonstrated excellent performance in organic light‐emitting diodes, yet their potential in organic solar cells (OSCs) remains underexplored. In this study, a novel metal–organic complex, Pt‐Y, which features a platinum core connected to Y‐acceptor arms, for application in OSCs is designed and synthesized. The dimerized...

Oligomerized electron acceptors, featuring molecular weights akin to polymers and well‐defined chemical structures, have emerged as promising candidates for organic solar cells (OSCs) due to their consistent batch‐to‐batch reproducibility and improved thermal stability. In this study, we developed a series of oligomerized electron acceptors incorpo...

Developing solution‐processed, thickness‐insensitive hole‐transporting layers (HTLs) is a key challenge in scaling high‐performance organic solar cells (OSCs). Here, a simple and efficient method is presented to produce highly conductive molybdenum oxide (MoOx) HTLs by n‐doping ammonium heptamolybdate with a reductive ionic liquid (IL). Owing to th...

Inorganic metal oxides and salts are widely employed as hole‐transporting layers (HTLs) in organic solar cells (OSCs) due to their advantages of low cost and facile preparation. However, issues such as severe agglomeration can negatively impact film quality, leading to reduced reproducibility and device stability. To address these challenges, this...

Star‐shaped conjugated materials exhibit monodisperses, well‐defined structures akin to small molecules while possessing the high molecular weights typical of polymers, making them appealing for organic electronics. Herein, a series of star‐shaped electron acceptors, labeled SP1‐Ph, SP2‐Ph, SP3‐Ph, SP4‐Ph, and SP6‐Ph correspond to one to six number...

A novel isotropic fullerene‐hybridized fused‐ring electron acceptor, designated C60‐Y, has been synthesized via a mild [4+2] Diels–Alder cycloaddition reaction with fullerene C60 to enhance the performance of organic solar cells (OSCs). Comparative analysis shows that C60‐Y significantly outperforms the control acceptor Me−Y, with a notable increas...

A novel isotropic fullerene‐hybridized fused‐ring electron acceptor, designated C60‐Y, has been synthesized via a mild [4+2] Diels‐Alder cycloaddition reaction with fullerene C60 to enhance the performance of organic solar cells (OSCs). Comparative analysis shows that C60‐Y significantly outperforms the control acceptor Me‐Y, with a notable increas...

Silver nanowires (AgNWs) deposited on plastic substrates show potential as electrodes for flexible electronics but face challenges due to high surface roughness and poor compatibility with organic plastics. To overcome these issues, this study incorporates calcium alginate, a cross-linked polymer binder, into the electrodes through the cross-linkin...

Copper(I) thiocyanate (CuSCN) is a prominent wide‐bandgap p‐type semiconductor with desirable transparency and chemical robustness. Whereas intrinsic limitations, such as its relatively low Fermi level (EF) and modest electrical conductivity, have impeded its broader application in organic solar cells (OSCs). This study introduces a novel approach...

Volatile solid additives have emerged as a promising strategy for enhancing film morphology and promoting the power conversion efficiency (PCE) of organic solar cells (OSCs). Herein, a series of novel polycyclic aromatic additives with analogous chemical structures, including fluorene (FL), dibenzothiophene (DBT), and dibenzofuran (DBF) derived fro...

Ternary organic solar cells (T‐OSCs) represent an efficient strategy for enhancing the performance of OSCs. Presently, the majority of high‐performance T‐OSCs incorporates well‐established Y‐acceptors or donor polymers as the third component. In this study, a novel class of conjugated small molecules has been introduced as the third component, demo...

Ternary organic solar cells (T‐OSCs) represent an efficient strategy for enhancing the performance of OSCs. Presently, the majority of high‐performance T‐OSCs incorporates well‐established Y‐acceptors or donor polymers as the third component. In this study, a novel class of conjugated small molecules has been introduced as the third component, demo...

Solvent additives are pivotal for enhancing the morphology, efficiency, and stability of organic solar cells (OSCs). However, the widely used additive, 1,8‐diiodooctane (DIO), has drawbacks like harmful halogen content and potential OSC degradation. To address these issues, novel non‐halogenated, thienyl‐alkyl‐thienyl structural solvent additives—D...

Incorporating flexible insulating polymers is a straightforward strategy to enhance the mechanical properties of rigid conjugated polymers, enabling their use in flexible electronic devices. However, maintaining electronic characteristics simultaneously is challenging due to the poor miscibility between insulating polymers and conjugated polymers....

Inspired by the multi roles of liquid crystal molecules, which exhibit both crystalline and liquid characteristics, we report a new solid additive, CB8-Br, by combining a biphenyl mesogenic unit and...

Stretchable transparent electrodes (STEs) have garnered considerable attention as a fundamental architectural component in the realm of conformable and wearable electronics. This study presents a novel approach utilizing composite inks based on silver nanowires to fabricate STEs, with the incorporation of a conductive polymer as the leveling agent...

Nickel oxide (NiO x ) has garnered considerable attention as a prospective hole‐transporting layer (HTL) in organic solar cells (OSCs), offering a potential solution to the stability challenges posed by traditional HTL, PEDOT:PSS, arising from acidity and hygroscopicity. Nevertheless, lower work function (WF) of NiO x relative to donor polymers red...

A pyrene‐fused dimerized electron acceptor has been successfully synthesized and subsequently incorporated as the third component in ternary organic solar cells (OSCs). Diverging from the traditional dimerized acceptors with a linear configuration, this novel electron acceptor displays a distinctive “butterfly‐like” structure, comprising two Y‐acce...

A pyrene‐fused dimerized electron acceptor has been successfully synthesized and subsequently incorporated as the third component in ternary organic solar cells (OSCs). Diverging from the traditional dimerized acceptors with a linear configuration, this novel electron acceptor displays a distinctive "butterfly‐like" structure, comprising two Y‐acce...

The electron transport layer ETL is essential for achieving high performance and stability of organic solar cells. However, most organic ETLs suffer from low conductivity, low electron mobility, and difficult modification, resulting in mitigation of charge collection and transport. Metal‐organic complex, such as ferrocene, is a promising candidate...

The exploration of blending insulating and conjugated polymers has been driven by wearable electronics, which needs materials with both high charge mobility and mechanical durability. Previous attempts faced challenges in achieving compatibility between insulating polymers and conjugated polymers. Our work addressed this issue through the identific...

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 multiple non‐covalent interactions...

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 record power conversion efficiency of solution-processed organic solar cells (OSCs) has almost doubled since non-fullerene acceptors (NFAs) replaced fullerene derivatives as the best-performing acceptor molecules. The successful transition from C60 to NFAs is still pending for vacuum-thermal evaporated (VTE) OSCs, not least because most NFAs ar...

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...

Recent studies have brought to the forefront the great potential of organic solar cells (OSCs) for their merits in energy-efficient devices under diminished illuminations, specifically indoor light sources. In this...

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...

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, 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...

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...

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...

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...

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...