Inverse design workflow discovers hole-transport materials tailored for perovskite solar cells.

The inverse design of tailored organic molecules for specific optoelectronic devices of high complexity holds an enormous potential but has not yet been realized. Current models rely on large data sets that generally do not exist for specialized research fields. We demonstrate a closed-loop workflow that combines high-throughput synthesis of organic semiconductors to create large datasets and Bayesian optimization to discover new hole-transporting materials with tailored properties for solar cell applications.

Structurally Compact Penta(N,N-diphenylamino)corannulene as Dopant-free Hole Transport Materials for Stable and Efficient Perovskite Solar Cells.

Hole transport materials (HTMs) are essential for improving the stability and efficiency of perovskite solar cells (PSCs). In this study, we have designed and synthesized a novel organic small molecule HTM, cor-(DPA), characterized by a bowl-shaped core with symmetric five diphenylamine groups. Compared to already-known HTMs, the bowl-shaped and relatively compact structure of cor-(DPA) facilitates intermolecular π-π interactions, promotes film formations, and enhances charge transport.

Design and Performance of Small-Molecule Donors with Donor-π-Acceptor Architecture Toward Vacuum-Deposited Organic Photovoltaics Having Heretofore Highest Short-Circuit Current Density.

The development of high-performance organic photovoltaic materials is of crucial importance for the commercialization of organic solar cells (OSCs). Herein, two structurally simple donor-π-conjugated linker-acceptor (D-π-A)-configured small-molecule donors with methyl-substituted triphenylamine as D unit, 1,1-dicyanomethylene-3-indanone as A unit, and thiophene or furan as π-conjugated linker, named DTICPT and DTICPF, are developed. DTICPT and DTICPF are facilely prepared via a two-step synthetic process with simple procedures.

Bridge effect on charge transfer and energy transfer in fullerene-chromophore dyads.

Fullerene-chromophore dyads have attracted a great deal of research interest because these complexes can be potentially designed as nanoscale artificial photosynthetic centers, in which the chromophore and fullerene function as the electron donor and acceptor, respectively. The basic operation of this dyad-type artificial reaction center is photoinduced electron transfer from the donor to the acceptor. The fullerene and chromophore are usually covalently linked so that sufficient electronic coupling between these two moieties can facilitate the electron transfer.

Molecular Tweezer Based on Perylene and Crown Ether for Selective Recognition of Fullerenes.

A molecular tweezer -di(perylene-3-ylmethanaminobenzo)-18-crown-6 (DP-18C6) incorporating two perylene subunits in a single crown ether core was designed and synthesized as a host for fullerenes. Through the cooperative effect of the perylene subunits and the crown ether moiety, DP-18C6 can efficiently recognize fullerenes including C, C, and C. H NMR titration and fluorescence titration experiments demonstrated that DP-18C6 can effectively grasp the fullerene molecule to form a 1:1 host-guest complex.

Progress in Antiviral Fullerene Research.

Unlike traditional small molecule drugs, fullerene is an all-carbon nanomolecule with a spherical cage structure. Fullerene exhibits high levels of antiviral activity, inhibiting virus replication in vitro and in vivo. In this review, we systematically summarize the latest research regarding the different types of fullerenes investigated in antiviral studies.

Surface Re-Engineering of Perovskites with Buckybowls to Boost the Inverted-Type Photovoltaics.

Despite their multifaceted advantages, inverted perovskite solar cells (PSCs) still suffer from lower power conversion efficiencies (PCEs) than their regular counterparts, which is largely due to recombination energy losses () that arise from the chemical, physical, and energy level mismatches, especially at the interfaces between perovskites and fullerene electron transport layers (ETLs). To address this problem, we herein introduce an aminium iodide derivative of a buckybowl (aminocorannulene) that is molecularly layered at the perovskite-ETL interface. Strikingly, besides passivating the PbI-rich perovskite surface, the aminocorannulene enforces a vertical dipole and enhances the surface n-type character that is more compatible with the ETL, thus boosting the electron extraction and transport dynamics and suppressing interfacial .

Synthesis and Fluorescent Properties of Multi-Functionalized C Derivatives of C(OCH)[C(COOEt)] and C(OCH)[C(COOEt)].

Due to the partially reduced π-conjugation of the fullerene cage, multi-functionalized fullerene derivatives exhibit remarkable fluorescent properties compared to pristine fullerenes, which have high potential for application in organic light-emitting diodes (OLEDs). In this study two multi-functionalized C derivatives, C(OCH)[C(COOEt)] and C(OCH)[C(COOEt)], with excellent fluorescence properties, were designed and synthesized. Compared with C(OCH) containing a single kind of functional group, both the C(OCH)[C(COOEt)] and C(OCH)[C(COOEt)] exhibited enhanced fluorescence properties with blue fluorescence emission.

Mixed Fullerene Electron Transport Layers with Fluorocarbon Chains Assembling on the Surface: A Moisture-Resistant Coverage for Perovskite Solar Cells.

In structure perovskite solar cells (PSCs), the most prevalent electron transport layer (ETL), [6, 6]-phenyl-C-butyric acid methyl ester (PCBM), acts as both electron extractor and protective coverage to the underlayer perovskite. Notably, multifunctional mixed fullerene ETLs show great potential in further improving both the power conversion efficiency (PCE) and stability of PSCs compared to the single PCBM ETL. In this work, we reported the mixed fullerene ETLs comprising of PCBM and its two analogs with different length of fluorocarbon chains, [6, 6]-phenyl-C-buryric acid 1H,1H-trifluoro-1-ethyl ester (abbreviated, CF-PCBM) and [6, 6]-phenyl-C-buryric acid 1H, 1H-tridecafluoro-1-heptyl ester (abbreviated, CF-PCBM).

Hybrid Fullerene-Based Electron Transport Layers Improving the Thermal Stability of Perovskite Solar Cells.

The structure-dependent thermal stability of fullerene electron transport layers (ETLs) and its impact on device stability have been underrated for years. Based on cocrystallographic understanding, herein, we develop a thermally stable ETL comprising a hybrid layer of [6,6]-phenyl-C-butyric acid methyl ester (PCBM) and [6,6]-phenyl-C-propylbenzene (PCPB). By tuning the weight ratios of PCBM and PCPB to influence the noncovalent intermolecular interactions and packing of fullerene derivatives, we obtained a champion device based on the 20PCPB (20 wt % addition of PCPB into the mixture of PCBM/PCPB) ETL and excellent thermal stability of 500 h under 85 °C thermal aging in a N atmosphere in the dark.

Low-Temperature Aging Provides 22% Efficient Bromine-Free and Passivation Layer-Free Planar Perovskite Solar Cells.

Previous reports of formamidinium/methylamine (FAMA)-mixed halide perovskite solar cells have focused mainly on controlling the morphology of the perovskite film and its interface-for example, through the inclusion of bromine and surface passivation. In this paper, we describe a new processing pathway for the growth of a high-quality bromine-free FAMAPbI halide perovskites via the control of intermediate phase. Through low-temperature aging growth (LTAG) of a freshly deposited perovskite film, α-phase perovskites can be seeded in the intermediate phase and, at the same time, prevent beta-phase perovskite to nucleate.

Pyridine-Functionalized Fullerene Electron Transport Layer for Efficient Planar Perovskite Solar Cells.

In regular perovskite solar cells (PSCs), the commonly used electron transport layer (ETL) is titanium oxide (TiO). Nevertheless, the preparation of a high-quality TiO ETL demands an elevated-temperature sintering procedure, unfavorable for fabrication of PSCs on flexible substrates. Besides, TiO-based devices often suffer from notorious photocurrent hysteresis and serious light soaking instability, limiting their potential commercialization.

Di-isopropyl ether assisted crystallization of organic-inorganic perovskites for efficient and reproducible perovskite solar cells.

Organic-inorganic perovskite solar cells have emerged as a promising photovoltaic technology because of their advantages such as low cost, high efficiency, and solution processability. The performance of perovskite solar cells is highly dependent on the crystallinity and morphology of the perovskite films. Herein, we report a simple, one-step anti-solvent deposition process using di-isopropyl ether as a dripping solvent to obtain extremely uniform and highly crystalline CHNHPbI perovskite films.

Solution-Processed Cu(In, Ga)(S, Se) Nanocrystal as Inorganic Hole-Transporting Material for Efficient and Stable Perovskite Solar Cells.

Perovskite solar cells are emerging as one of the most promising candidates for solar energy harvesting. To date, most of the high-performance perovskite solar cells have exclusively employed organic hole-transporting materials (HTMs) such as 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) or polytriarylamine (PTAA) which are often expensive and have low hole mobility. Almost all these HTMs reported needed lithium salt, e.

Tailorable PC BM Isomers: Using the Most Prevalent Electron Acceptor to Obtain High-Performance Polymer Solar Cells.

Despite being widely used as electron acceptor in polymer solar cells, commercially available PC BM (phenyl-C -butyric acid methyl ester) usually has a "random" composition of mixed regioisomers or stereoisomers. Here PC BM has been isolated into three typical isomers, α-, β - and β -PC BM, to establish the isomer-dependent photovoltaic performance on changing the ternary composition of α-, β - and β -PC BM. Mixing the isomers in a ratio of α/β /β =8:1:1 resulted in the best power conversion efficiency (PCE) of 7.

Efficient Perovskite Solar Cells Depending on TiO2 Nanorod Arrays.

Perovskite solar cells (PSCs) with TiO2 materials have attracted much attention due to their high photovoltaic performance. Aligned TiO2 nanorods have long been used for potential application in highly efficient perovskite solar cells, but the previously reported efficiencies of perovskite solar cells based on TiO2 nanorod arrays were underrated. Here we show a solvothermal method based on a modified ketone-HCl system with the addition of organic acids suitable for modulation of the TiO2 nanorod array films to fabricate highly efficient perovskite solar cells.

Combustion synthesis and electrochemical properties of the small hydrofullerene C50H10.

The hydrofullerene C(50)H(10) is synthesized by low-pressure benzene-oxygen diffusion combustion. The structure of C(50)H(10) is identified through NMR, mass spectrometry, and IR and Raman spectroscopy as a D(5h) symmetric closed-cage molecule with five pairs of fused pentagons stabilized by ten hydrogen atoms. UV/Vis and fluorescence spectrometric analyses disclose its optical properties as comparable with those of its chloride cousin (C(50)Cl(10)).