Abstract
Bulk-heterojunction (BHJ) organic solar cells (OSCs) are prepared by a common one-step solution casting of donor-acceptor blends often encounter dynamic morphological evolution which is hard to control to achieve optimal performance. To overcome this hurdle, a generally applicable, sequential processing approach has been developed to construct high-performance OSCs without involving tedious processes. The morphology of photoactive layers comprising a polymer donor (PM6) and a nonfullerene acceptor (denoted as Y6-BO) can be precisely manipulated by tuning Y6-BO layer with a small amount of 1-chloronaphthalene additive to induce the structural order of Y6-BO molecules to impact the blend phase. The results of a comparative investigation elucidate that such two-step procedure can afford more favorable BHJ microstructure than that achievable with the single blend-casting route. This translates into improved carrier generation and transport, and suppressed charge recombination. Consequently, the devices based on sequential deposition (SD) deliver a remarkable efficiency up to 17.2% (the highest for SD OSCs to date), outperforming that from the conventional BHJ devices (16.4%). The general applicability of this approach has also been tested on several other nonfullerene acceptors which show similar improvements. These results highlight that SD is a promising processing alternative to promote better photovoltaic performance and reduce production requirements.
| Original language | English |
|---|---|
| Article number | 2000687 |
| Journal | Small Methods |
| Volume | 4 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 2020 Dec 11 |
Bibliographical note
Funding Information:This work was supported by the APRC Grant of the City University of Hong Kong (9610421), Innovation and Technology Fund (ITS/497/18FP, GHP/021/18SZ), the Office of Naval Research (N00014‐20‐1‐2191), the Early Career Scheme Grant (CityU 21301319) from the Research Grants Council (RGC) of Hong Kong, Natural Science Foundation of Guangdong Province (2019A1515010761), Guangdong Major Project of Basic and Applied Basic Research (No. 2019B030302007), Guangdong‐Hong Kong‐Macao joint laboratory of optoelectronic and magnetic functional materials (No. 2019B121205002), the Fundamental Research (Discipline Arrangement) Project funding from the Shenzhen Science and Technology Innovation Committee (No. JCYJ20180507181718203). H.Y.W. is grateful for the financial support from the National Research Foundation (NRF) of Korea (NRF‐2016M1A2A2940911 and 2019R1A6A1A11044070). The authors thank Material Characterization and Preparation Facility (MCPF) of Hong Kong University of Science and Technology for carrying out TOF‐SIMS measurement.
Funding Information:
This work was supported by the APRC Grant of the City University of Hong Kong (9610421), Innovation and Technology Fund (ITS/497/18FP, GHP/021/18SZ), the Office of Naval Research (N00014-20-1-2191), the Early Career Scheme Grant (CityU 21301319) from the Research Grants Council (RGC) of Hong Kong, Natural Science Foundation of Guangdong Province (2019A1515010761), Guangdong Major Project of Basic and Applied Basic Research (No. 2019B030302007), Guangdong-Hong Kong-Macao joint laboratory of optoelectronic and magnetic functional materials (No. 2019B121205002), the Fundamental Research (Discipline Arrangement) Project funding from the Shenzhen Science and Technology Innovation Committee (No. JCYJ20180507181718203). H.Y.W. is grateful for the financial support from the National Research Foundation (NRF) of Korea (NRF-2016M1A2A2940911 and 2019R1A6A1A11044070). The authors thank Material Characterization and Preparation Facility (MCPF) of Hong Kong University of Science and Technology for carrying out TOF-SIMS measurement.
Publisher Copyright:
© 2020 Wiley-VCH GmbH
Keywords
- morphology control
- organic solar cells
- power conversion efficiencies
- sequential deposition
ASJC Scopus subject areas
- Materials Science(all)
- Chemistry(all)
