Synthesis and Characterization of a New Wide Bandgap Donor Polymer through Direct Arylation Polycondensation Method for Enhanced Performance in Ternary Non-Fullerene Organic Solar Cells.

The ternary active layer approach has emerged as a promising approach to further boost the power conversion efficiency of organic solar cells. In order to absorb photons from the solar radiation below 600 nm, we have designed and synthesized a new wide bandgap polymer P(FCzNDT-DFTPhz) consisting of strong 5,6-bis(6-fluoro-9H-carbazol-3-yl)naphtho[2,1-b:3,4-b']dithiophene and di-fluoro-dithieno [3,2-a:2',3'-c]phenazine donor and acceptor units, respectively, its optical and electrochemical properties were investigated. The P(FCzNDT-DFTPhz) exhibits strong absorption spectrumbelow 650 nm along with deeper HOMO energy level (-5.

BODIPY-Coumarin Triad as Acceptor for Ternary Nonfullerene Solar Cells with over 15% Efficiency.

Herein, a new nonfused fullerene-free acceptor is synthesized based on the BODIPY-coumarin triad, BDP-2C, which exhibits a medium optical bandgap of about 1.51 eV, and HOMO and LUMO energy levels of about -5.50 and -4.

Enhanced Charge and Energy Transfer in All-Small-Molecule Ternary Organic Solar Cells: Transient Photocurrent and Photovoltage and Transient Photoluminescence Measurements.

A donor-acceptor-donor (D-A-D) molecule, denoted as RC18, consisting of two nickel-porphyrin terminal donor units (D) and a selenophene-flanked diketopyrrolopyrrole central core, connected via an ethynylene linker has been synthesized. The highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels were measured showing values of -5.49 eV and -3.

Organic Solar Cells Based on Non-Fullerene Low Molecular Weight Organic Semiconductor Molecules.

The development of narrow bandgap A-D-A- and ADA'DA-type non-fullerene small molecule acceptors (NFSMAs) along with small molecule donors (SMDs) have led to significant progress in all-small molecule organic solar cells. Remarkable power conversion efficiencies, nearing the range of 17-18 %, have been realized. These efficiency values are on par with those achieved in OSCs based on polymeric donors.

Halogenation Strategy: Simple Wide Band Gap Nonfullerene Acceptors with the BODIPY-Thiophene-Backboned Polymer Donor for Enhanced Outdoor and Indoor Photovoltaics.

Researchers have been motivated to develop photovoltaic systems that can efficiently convert artificial light into power with the growing use of indoor electrical devices for the Internet of Things. Understanding the impact of molecular design strategies involving morphological optimization through the terminal group of the non-fullerene acceptors (NFAs) is crucial. This is critically important to enhancing the photovoltaic efficiency of organic photovoltaic devices under diverse irradiation conditions.

Small molecular donor materials based on --bridged BODIPY dimers with a triphenylamine or carbazole unit for efficient organic solar cells.

Herein, we have designed and synthesized two novel BODIPY dimer-based small molecules, denoted as ZMH-1 and ZMH-2, covalently linked and functionalized with triphenylamine (TPA) (ZMH-1) and carbazole (C) (ZMH-2) units as the electron donor at the 3- and 5-positions of the BODIPY core, respectively. Their optical and electrochemical properties were investigated. We have fabricated all small molecule bulk heterojunction organic solar cells using these BODIPY-based small molecules as electron donors along with fullerene derivative (PCBM) and medium bandgap non-fullerene acceptor IDT-TC as electron acceptors.

An Asymmetric Coumarin-Anthracene Conjugate as Efficient Fullerene-Free Acceptor for Organic Solar Cells.

Asymmetric wide-band gap fullerene-free acceptors (FFAs) play a crucial role in organic solar cells (OSCs). Here, we designed and synthesized a simple asymmetric coumarin-anthracene conjugate named CA-CN with optical band gap of 2.1 eV in a single-step condensation reaction.

Directed Message Passing Neural Network for Predicting Power Conversion Efficiency in Organic Solar Cells.

Organic solar cells (OSCs) have emerged as a promising technology for renewable energy generation, and researchers are constantly exploring ways to improve their efficiency. For prediction of photovoltaic properties in OSCs, many machine learning models have been used in the past. All the models are used with fixed molecular descriptors and molecular fingerprints as input for power conversion efficiency (PCE) prediction.

Effects of Halogenation on Cyclopentadithiophenevinylene-Based Acceptors with Excellent Responses in Binary Organic Solar Cells.

In recent years, non-fused non-fullerene acceptors (NFAs) have attracted increasing consideration due to several advantages, which include simple preparation, superior yield, and low cost. In the work reported here, we designed and synthesized three new NFAs with the same cyclopentadithiophenevinylene (CPDTV) trimer as the electron-donating unit and different terminal units (IC for , IC-4F for , and IC-4Cl for ). Both halogenated NFAs, i.

Simple and Efficient Acceptor-Donor-Acceptor-Type Non-fullerene Acceptors for a BODIPY-Thiophene-Backboned Polymer Donor for High-Performance Indoor Photovoltaics.

Herein, simple acceptor-donor-acceptor (A-D-A)-type small molecules denoted as DICTF and DRCTF with modification in terminal units were synthesized and used as electron acceptors. With the tuning of the electron-withdrawing units in electron acceptors, their photovoltaic properties were investigated when combined with low-band-gap BODIPY-thiophene-backboned donor material, named P(BdP-HT). The P(BdP-HT):DICTF-based organic solar cells (OSCs) displayed excellent efficiency of around 11.

Harnessing the Structure-Performance Relationships in Designing Non-Fused Ring Acceptors for Organic Solar Cells.

The prerequisite for commercially viable organic solar cells (OSC) is to reduce the efficiency-stability-cost gap. Therefore, the cost of organic materials should be reduced by minimizing the synthetic steps, yet maintaining the molecular planarity and efficiencies achieved by the fused ring acceptors (FRA). In this respect, developing non-fused ring acceptors (NFRA) with suitable functionalization to favor conformational planarity and effective molecular packing is beneficial and cost-effective.

Medium Bandgap Nonfullerene Acceptor for Efficient Ternary Polymer Solar Cells with High Open-Circuit Voltage.

We have designed a new medium bandgap non-fullerene small-molecule acceptor consisting of an IDT donor core flanked with 2-(6-oxo-5,6-dihydro-4-cyclopenta[]-thiophene-4-ylidene) malononitrile (TC) acceptor terminal groups () and compared its optical and electrochemical properties with the IDT-IC acceptor. showed an absorption profile from 300 to 760 nm, and it has an optical bandgap of 1.65 eV and HOMO and LUMO energy levels of -5.

Role of Exciton Lifetime, Energetic Offsets, and Disorder in Voltage Loss of Bulk Heterojunction Organic Solar Cells.

Recently, the power conversion efficiency (PCE) of organic solar cells (OSCs) has significantly progressed with a rapid increase from 10 to 19% due to state-of-the-art research on nonfullerene acceptor molecules and various device processing strategies. However, OSCs still exhibit significant open circuit voltage loss (Δ ∼ 0.6 V) due to high energetic offsets and molecular disorder.

Active Discovery of Donor:Acceptor Combinations For Efficient Organic Solar Cells.

The structural flexibility of organic semiconductors offers vast a search space, and many potential candidates (donor and acceptor) for organic solar cells (OSCs) are yet to be discovered. Machine learning is extensively used for material discovery but performs poorly on extrapolation tasks with small training data sets. Active learning techniques can guide experimentalists to extrapolate and find the most promising D:A combination in a significantly small number of experiments.

Efficient Medium Bandgap Electron Acceptor Based on Diketopyrrolopyrrole and Furan for Efficient Ternary Organic Solar Cells.

We report the design of novel medium bandgap nonfullerene small molecule acceptor NFSMA with A-π-A-π-A architecture, with the molecular engineering of this material comprising a strong electron-accepting backbone unit DPP (A) as the acceptor, which is attached to the dicyanomethylene-3-hexylrhodanine (A) acceptor via a furan (π-spacer) linker. We systematically studied its structural and optoelectronic properties. The incorporation of dicyanomethylene-3-hexylrhodanine and furan enhance the light absorption and electrochemical properties by extending π-conjugation and is anticipated to improve by decreasing the LUMO level.

Novel Pyrrolo [3,4-b] Dithieno [3, 2-f:2″,3″-h] Quinoxaline-8,10 (9H)-Dione Based Wide Bandgap Conjugated Copolymers for Bulk Heterojunction Polymer Solar Cells.

Two D-A copolymers consisting of fused ring pyrrolo-dithieno-quinoxaline acceptors are synthesized with different donor units, i.e., benzodithiophene (BDT) with alkylthienyl (P134) and 2-ethylhexyloxy (P117) side chains.

Gold(III) Porphyrin Was Used as an Electron Acceptor for Efficient Organic Solar Cells.

The widespread use of nonfullerene-based electron-accepting materials has triggered a rapid increase in the performance of organic photovoltaic devices. However, the number of efficient acceptor compounds available is rather limited, which hinders the discovery of new, high-performing donor:acceptor combinations. Here, we present a new, efficient electron-accepting compound based on a hitherto unexplored family of well-known molecules: gold porphyrins.

New Medium Bandgap Donor D-A -D-A Type Copolymers Based on Anthra[1,2-b: 4,3-b":6,7-c"'] Trithiophene-8,12-dione Groups for High-Efficient Non-Fullerene Polymer Solar Cells.

A new acceptor unit anthra[1,2-b: 4,3-b': 6,7-c'']trithiophene-8,12-dione (А3Т) (A2) is synthesized and used to design D-A -D-A medium bandgap donor copolymers with same thiophene (D) and A2 units but different A1, i.e., fluorinated benzothiadiazole (F-BTz) and benzothiadiazole (BTz) denoted as P130 and P131, respectively.

Binary and Ternary Polymer Solar Cells Based on a Wide Bandgap D-A Copolymer Donor and Two Nonfullerene Acceptors with Complementary Absorption Spectral.

A new wide-bandgap conjugated D-A polymer denoted as P106 with a medium acceptor dithieno [2,3-e;3'2'-g]isoindole-7,9 (8H) (DTID) unit and strong 2-dodecylbenzo[1,2-b:3,4-b':6,5-b"]trithiophene (3TB) donor units shows an optical bandgap of 2.04 and highest occupied molecular orbital energy level of -5.56 eV.

Fullerene/Non-fullerene Alloy for High-Performance All-Small-Molecule Organic Solar Cells.

Organic solar cells (OSCs) that contain small molecules only were prepared with as the donor, a narrow band gap non-fullerene acceptor , and a wide band gap PCBM. The OSCs based on optimized : (1:1.2) and :PCBM (1:1.

Reducing Energy Loss in Organic Solar Cells by Changing the Central Metal in Metalloporphyrins.

The effect of central donor core on the properties of A-π-D-π-A donors, where D is a porphyrin macrocycle, cyclopenta[2,1-b:3,4-b']dithiophene is the π bridge, and A is a dicyanorhodanine terminal unit, was investigated for the fabrication of the organic solar cells (OSCs), along [6,6]-phenyl-C71-butyric acid methyl ester (PC BM) as electron acceptor. A new molecule consisting of Ni-porphyrin central donor core (VC9) showed deep HOMO energy level and OSCs based on optimized VC9:PC BM realized overall power conversion efficiency (PCE) of 10.66 % [short-circuit current density (J )=15.

Efficient Fullerene-Free Organic Solar Cells Using a Coumarin-Based Wide-Band-Gap Donor Material.

In recent years, tremendous growth has been seen for solution-processed bulk heterojunction solar cells (BHJSCs) using fullerene-free molecular acceptors. Herein, we report the synthesis, characterization of a coumarin-based organic semiconducting molecule C1, and its use in BHJSCs as an electron donor. The compound exhibited an absorption band at 472 nm in chloroform solution with an optical energy gap of 2.

Carbazole-based green and blue-BODIPY dyads and triads as donors for bulk heterojunction organic solar cells.

Two BODIPY derivatives with one (B2) and two (B3) carbazole moieties were synthesized and applied as electron-donor materials in organic photovoltaic cells (OPV). Their optical and electrochemical properties were systematically investigated. These BODIPY dyes exhibit excellent solubility in organic solvents and present high molar extinction coefficients (1.