Abstract
Nickel oxide (NiO) is used as a hole-transporting layer (HTL) in perovskite solar cells (PSCs) because of its high optical transmittance, intrinsic p-type doping, and suitable valence band energy level. However, fabricating high-quality NiO films typically requires high-temperature annealing, which limits their applicability for low-temperature, printable PSCs. Herein, the need for such postprocessing steps is circumvented by coupling 4-hydroxybenzoic acid (HBA) or trimethyloxonium tetrafluoroborate (Me3OBF4) ligand-modified NiO nanoparticles (NPs) with a Tesla-valve microfluidic mixer to deposit high-quality NiO films at a temperature <150 °C. The NP dispersions and the resulting thin films are thoroughly characterized using a combination of optical, structural, thermal, chemical, and electrical methods. While the optical and structural properties of the ligand-exchanged NiO NPs remain comparable with those possessing the native long-chained aliphatic ligands, the ligand-modified NiO thin films exhibit dramatic reductions in surface energy and an increase in hole mobilities. These are correlated with concomitant and significant enhancements in performance and stability factors of PSCs when the ligand-modified NiO NPs are used as HTL layers within p−i−n device architectures.
| Original language | English |
|---|---|
| Article number | 2100342 |
| Journal | Solar RRL |
| Volume | 5 |
| Issue number | 8 |
| DOIs | |
| State | Published - Aug 2021 |
| Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2021 Wiley-VCH GmbH
Funding
M.M. and M.A.S. contributed equally to this work. U.B. and J.J. coshare corresponding authorship. The authors are grateful for the financial support by the ARC discovery project (DP160104575), the Australian Centre for Advanced Photovoltaics (ACAP), the Australian Renewable Energy Agency (2017/RND012), and the ARC Centre of Excellence in Exciton Science (ACEx, CE170100026). The authors acknowledge the use of instruments and scientific and technical assistance at the Monash Centre for Electron Microscopy, a Node of Microscopy Australia. The authors acknowledge the use of facilities at CSIRO Flexible Electronics Laboratory. This work was conducted in part at the Melbourne Centre for Nanofabrication (MCN) in the Victorian Node of the Australian National Fabrication Facility (ANFF). This work was conducted in part at the South Australia node of the Australian National Fabrication Facility, a company established under the National Collaborative Research Infrastructure Strategy to provide nano‐ and microfabrication facilities for Australia's researchers. The authors acknowledge use of the facilities and the assistance of Dr. James Griffith at the Monash X‐ray Platform. The authors acknowledge help related to field‐effect transistor (FET) device fabrication from Professor Paul Mulvaney and his group at University of Melbourne. The authors acknowledge help related to FET device substrates and use of the in‐house measurement kit of Professor Chris McNeill's group at Monash University. The authors want to acknowledge invaluable help in semiconductor‐related topics received from Mr. Dan Smith and for fullerene thermal evaporation from Dr. Ash Dyer, both from MCN. M.A.S. acknowledges Dr. Nick Scarratt (Osilla Ltd Sheffield, UK) for the help related to troubleshooting of the custom measurement system. M.M. and M.A.S. contributed equally to this work. U.B. and J.J. coshare corresponding authorship. The authors are grateful for the financial support by the ARC discovery project (DP160104575), the Australian Centre for Advanced Photovoltaics (ACAP), the Australian Renewable Energy Agency (2017/RND012), and the ARC Centre of Excellence in Exciton Science (ACEx, CE170100026). The authors acknowledge the use of instruments and scientific and technical assistance at the Monash Centre for Electron Microscopy, a Node of Microscopy Australia. The authors acknowledge the use of facilities at CSIRO Flexible Electronics Laboratory. This work was conducted in part at the Melbourne Centre for Nanofabrication (MCN) in the Victorian Node of the Australian National Fabrication Facility (ANFF). This work was conducted in part at the South Australia node of the Australian National Fabrication Facility, a company established under the National Collaborative Research Infrastructure Strategy to provide nano- and microfabrication facilities for Australia's researchers. The authors acknowledge use of the facilities and the assistance of Dr. James Griffith at the Monash X-ray Platform. The authors acknowledge help related to field-effect transistor (FET) device fabrication from Professor Paul Mulvaney and his group at University of Melbourne. The authors acknowledge help related to FET device substrates and use of the in-house measurement kit of Professor Chris McNeill's group at Monash University. The authors want to acknowledge invaluable help in semiconductor-related topics received from Mr. Dan Smith and for fullerene thermal evaporation from Dr. Ash Dyer, both from MCN. M.A.S. acknowledges Dr. Nick Scarratt (Osilla Ltd Sheffield, UK) for the help related to troubleshooting of the custom measurement system.
| Funders | Funder number |
|---|---|
| Australian Centre for Advanced Photovoltaics | |
| Australian Research Council | DP160104575 |
| Monash University | |
| Australian Renewable Energy Agency | 2017/RND012 |
| Centre of Excellence in Exciton Science | CE170100026 |
Keywords
- hole-transporting layers
- ligand exchanges
- low temperatures
- nickel oxide
- perovskite solar cells