Managing Challenges in Organic Photovoltaics: Properties and Roles of Donor/Acceptor Interfaces

Advanced Functional Materials, Journal Year: 2022, Volume and Issue: 32(43)

Published: Aug. 15, 2022

Abstract Organic photovoltaics (OPVs) have demonstrated increasing potential for use in large‐area, flexible, and light‐weight applications. To date, the rapid development of nonfullerene acceptors (NFAs) their conjugated polymeric donors increased efficiency OPV by over 19%. Nevertheless, is still suffering from high energy loss, which primarily derives donor (D)/acceptor (A) interfacial charge recombination. In particular, voltage loss occurring at D/A interface accounts current bottleneck, hampering further enhancement efficiency. this review, recent discovery photophysics NFA‐based OPVs, including comparison with its fullerene‐based counterpart, covered. Additionally, factors governing such as energetics local morphologies, causes trade‐off relationship between photovoltage photocurrent are highlighted. Accordingly, control properties to create an “ideal” generation OPVs reviewed; emphasized that modifications can serve a powerful tool manage challenges path toward future practical

Language: Английский

---

As‐Cast Ternary Organic Solar Cells Based on an Asymmetric Side‐Chains Featured Acceptor with Reduced Voltage Loss and 14.0% Efficiency

Advanced Functional Materials, Journal Year: 2020, Volume and Issue: 30(11)

Published: Jan. 22, 2020

Abstract A new small‐molecule nonfullerene acceptor based on the benzo[1,2‐ b :4,5‐ ′]dithiophene (BDT) fused central core with asymmetrical alkoxy and thienyl side chains, namely TOBDT , is designed synthesized. The unit helps narrow bandgap, chain enhance intermolecular interaction. As a result, suitable to match deep‐lying highest occupied molecular orbital (HOMO) of polymer donor PM6 . Then, strong crystalline IDIC introduced as third component fabricate as‐cast ternary devices achieve absorption morphology control. Addition not only mixes well but modulates blend film, which balance charge transport properties reduce photovoltage loss devices. All these contribute synergetic improvement J sc V oc fill factor parameters, leading power conversion efficiency 14.0% for fullerene‐free device.

Language: Английский

---

Simple Near-Infrared Electron Acceptors for Efficient Photovoltaics and Sensitive Photodetectors

ACS Applied Materials & Interfaces, Journal Year: 2020, Volume and Issue: 12(35), P. 39515 - 39523

Published: Aug. 10, 2020

Although promising progress has been made in near-infrared (NIR) electron acceptors for broadening photoresponse of optoelectronics, there are still strong needs efficient NIR materials with low synthetic complexities. In this work, three simple developed absorption up to 1000 nm and possessing the same dithiophene cores varied heteroatom linkages carbon (C) atom W1, silicon (Si) W2, nitrogen (N) W3. It is found that tuning only one can surprisingly lead a large difference photoelectric properties solid stacking, as well performance optoelectronics. quite simple, these acceptors, especially W1 (C), also perform efficiently organic photovoltaics (OPVs) sensitive photodetectors (OPDs) when blended PTB7-Th polymer. worthy note that, among representative over 950 absorption, possesses best figure-of-merit considering versus complexity materials. As result, PTB7-Th:W1-based OPDs reach fast temporal response, ultralow-light intensity detection 1.70 × 10-11 W·cm-2, high specific detectivity 4.28 1012 cm·Hz1/2·W-1 at 830 nm, representing highly self-powered OPD approach commercial broadband detectors. These structure provide potential example further application acceptor.

Language: Английский

---

Effects of Heteroatom Substitution on the Photovoltaic Performance of Donor Materials in Organic Solar Cells

Accounts of Materials Research, Journal Year: 2021, Volume and Issue: 2(11), P. 986 - 997

Published: Oct. 24, 2021

ConspectusOver the past few years, innovation of narrow bandgap acceptor combined with wide donor materials significantly promotes power conversion efficiencies (PCEs) organic solar cells (OSCs) to exceed 18%. To build a state-of-the-art OSC, absorption spectra, frontier molecular orbital energy levels, packing and crystallinity, charge carrier mobilities photovoltaic should be considered in their design. The are key components determining performance OSCs. side chain engineering on conjugated backbone is critical strategy optimize properties materials. In this Account, we focus topic heteroatom substitution for improving performance, aiming provide in-depth understanding structure optimization design materials.First, highlight halogen (fluorine chlorine) atom strategies applied strong electronegativity atoms can downshift highest occupied (HOMO) levels materials, which could increase open-circuit voltages resulting addition, hydrogen bonding aroused by beneficial improve transport property crystallinity semiconductors. On other hand, flexible chains solubility Using alkylthio alkylsilyl an easy effective approach tune electronic spectra Due formation pπ(C)–dπ(S) overlap, empty 3d-orbitals sulfur substituents accept π-electron skeleton modulate optical electrical Similarly, silicon stabilize lowest unoccupied (LUMO) level HOMO semiconductor, leads improved Finally, briefly discussed challenges toward practical application

Language: Английский

---

Designs and understanding of small molecule-based non-fullerene acceptors for realizing commercially viable organic photovoltaics

Chemical Science, Journal Year: 2021, Volume and Issue: 12(42), P. 14004 - 14023

Published: Jan. 1, 2021

This review describes the current understandings and significant features observed in NFA-based OPVs, with a particular focus on photophysical, electrical, morphological characteristics.

Language: Английский

---