Achieving 18.14% Efficiency of Ternary Organic Solar Cells with Alloyed Nonfullerene Acceptor

Abstract

The ternary strategy is an effective method to improve the efficiency of organic solar cells (OSCs). Herein, high‐performance OSCs with over 18% efficiency using PM6 as donor and alloy‐like acceptor containing two highly structurally similar acceptors (Y6 and Y6‐1O) is obtained. The spectral overlap of Y6 and Y6‐1O can increase the collection of photons via enhancing the absorption in near infrared region, which is conducive to improve the short‐circuit current density (J SC). Meanwhile, beneficial electron transport channels are established by the construction of cascaded energy levels of Y6 and Y6‐1O in the ternary films. In addition, compared with Y6‐ and Y6‐1O‐based binary devices, enhanced charge mobility and suppressed charge recombination are observed in the optimal ternary OSCs, contributing to better performance. The improved performance of ternary devices based on the introduction of Y6‐1O is also attributed to the enhancement of photon capture and improved charge extraction as well as optimized blend morphology. A very promising ternary strategy is presented with two highly compatible acceptors to synergize the device performance in the development of high‐efficient OSCs.

Design and Application of an Asymmetric Naphthalimide-based Molecule with Improved Hydrophobicity for Highly Stable Organic Solar Cells

“…The organic solar cell (OSC) has been considered as the next-generation photovoltaic technology with the advantage of fabricating large-area panel using the cost-effective solution processing method. − The power conversion efficiency (PCE) of the state-of-the-art OSC has exceeded 18%, reaching the threshold of practical use. − Compared to the advancement in PCE, the improvement in device stability is rather limited. − In particular, although OSCs with good storage stabilities in the dark or in an inert atmosphere have been reported, most devices exhibited dramatic performance decay in ambient conditions due to the fragility under external environmental factors. − In fact, it is an abnormal phenomenon that the pursuit of photovoltaic efficiency in the OSC field becomes the focus of attention, regardless of a long lifetime under the ambient conditions, and the neglect of a long lifetime makes no sense to an applied technology like organic photovoltaics . At present, the poor ambient stability has become the main bottleneck for the practical application of OSCs.…”

Photo‐induced energy and charge transfer dynamics in Y6 dimers

“…Recently, non‐fullerene acceptors (NFAs) are proposed to replace the fullerene molecules and the PCE of constructed OSCs can be up to 20%. [ 5–17 ] The possible reason may be from easily implementing electronic structure properties of NFAs to match with the properties of donor molecules and improve carrier transfer behavior. [ 18–20 ]…”

“…implementing electronic structure properties of NFAs to match with the properties of donor molecules and improve carrier transfer behavior. [18][19][20] Among many of NFAs, the Y6 molecule (BTP-4F) is becoming a star acceptor because the PCE from this acceptor can be up to a value for commercial applications, [5][6][7][8][9][10][11][12][13][14][15][16][17] and its electronic structure and photophysical processes have been extensively investigated. [21][22][23][24] It is now known that a single Y6 molecule has several donor-acceptor pairs performing the intramolecular electron push-pull effect, and can thus absorb near-infrared light.…”

Stable dinitrile end-capped closed-shell non-quinodimethane as a donor, an acceptor and an additive for organic solar cells

“…35 By selecting an appropriate third component, PCEs more than 18% have been reported for efficient ternary OSCs, which indicates tremendous potential for development. 36–42…”