April 22 - 26, 2024
Seattle, Washington
May 7 - 9, 2024 (Virtual)

Event Supporters

2024 MRS Spring Meeting
EN04.04.04

Dimerized Small-Molecule Acceptors Enable High-Performance Organic Solar Cells with High Open-Circuit Voltage and Prolonged Life-Time

When and Where

Apr 23, 2024
5:00pm - 7:00pm
Flex Hall C, Level 2, Summit

Presenter(s)

Co-Author(s)

Jinwoo Lee1,Cheng Sun2,Yun-Hi Kim2,Bumjoon Kim1

Korea Advanced Institute of Science and Technology1,Gyeongsang National University2

Abstract

Jinwoo Lee1,Cheng Sun2,Yun-Hi Kim2,Bumjoon Kim1

Korea Advanced Institute of Science and Technology1,Gyeongsang National University2
The power conversion efficiencies (PCEs) of small molecule acceptor (SMA)-based organic solar cells (OSCs) have remarkably increased in recent years, but their thermal and long-term stability are insufficient for commercialization. In addition, the low open-circuit voltage (<i>V</i><sub>oc</sub>) of OSCs, compared to those of other types of solar cells (<i>i.e.</i>, perovskite solar cells), should be addressed to further improve their PCEs. Here, we demonstrate that the dimerization of an SMA resolves the performance limitations of SMA-based OSCs, in terms of stability and <i>V</i><sub>oc</sub>. The dimerized SMA (DYBO) connected by a benzodithiophene (BDT) conjugated linker affords OSCs with excellent PCEs (&gt; 18%), which outperform OSCs based on its monomer counterpart (MYBO, PCE ~ 17.1%). The electron-donating BDT linker in DYBO effectively upshifts the lowest unoccupied molecular orbital energy level and reduces the voltage loss, synergistically increasing the <i>V</i><sub>oc</sub> of DYBO-based OSCs. Importantly, DYBO-based OSCs exhibit excellent thermal and photo stability. For example, DYBO-based OSCs retain more than 80% of their initial PCE even after 6000 hr of thermal exposure at 100 °C, whereas the PCE of MYBO-based OSCs sharply degrade to ~80% of their initial value in only 36 hr. The improved stability of DYBO-based OSCs is attributed to (1) the high glass transition temperature (<i>T</i><sub>g</sub>) of DYBO of 179 °C (the<i> T</i><sub>g</sub> of MYBO is 80 °C) due to its extended chain, which stabilizes the blend morphology under thermal stress, and (2) the improved miscibility of DYBO with the BDT-based polymer donor. Thus, we highlight the significance of the molecular design of dimerized SMAs in realizing OSCs with excellent PCEs and stabilities.

Keywords

thermal diffusivity | thin film

Symposium Organizers

Derya Baran, King Abdullah University of Science and Technology
Dieter Neher, University of Potsdam
Thuc-Quyen Nguyen, University of California, Santa Barbara
Oskar Sandberg, Åbo Akademi University

Symposium Support

Silver
Enli Technology Co., Ltd.

Bronze
1-Material, Inc.

Session Chairs

Oskar Sandberg

In this Session