Above: Scientists at the Department of Physics and Astronomy at the University of Sheffield (UK) have developed a spray-on method of producing solar cells that can potentially combine high efficiency and low-cost. Published on 6 Jun 2017
Fig 1: Organic photovoltaic devices fabricated onto a flexible plastic substrate (photo by Lucy Pickford).
Fig 2: Standard architecture perovskite photovoltaic devices.
Third generation thin-film photovoltaics (PV) are of significant interest
for low-cost generation of solar electricity, as they potentially combine reduced embodied
energy, with ease of manufacture using solution-based techniques. At Sheffield, we have a
detailed research programme into the development of photovoltaics based on two main types of
semiconducting materials (i) organo-metal halide perovkites and (ii) polymer:fullerene blends.
In both cases, such materials can be coated onto a surface using solution-based techniques
(including spray-coating), and then fabricated into a PV device. We are currently exploring
a range of different new perovskite and organic semiconductor materials, with our objective
being to optimise device efficiency, maximise device stability and to develop techniques
appropriate for device scale-up and manufacture. In our research, we use a range of
spectroscopic techniques to understand the electronic properties of the materials we develop,
together with other structural probes (including X-ray scattering) to understand thin-film
morphology over a range of length-scales.
We also have an outdoors testing facility at the Sheffield Solar Farm. This acts as a
long-term testing environment for photovoltaic devices made in the laboratory. Three
encapsulation chambers expose test devices to sunlight, whilst protecting them from moisture
and oxygen in an inert nitrogen atmosphere.
Fig 3: Hermetically sealed chambers protect new photovoltaic devices
while they undergo long-term testing at the Sheffield Solar farm. Photo by Ellie Scott, courtesy Ossila.
This Perspective summarizes the developments in spray-cast perovskite solar cells made over the past few years, with particular attention paid to strategies employed to control the crystallization of the perovskite. Steady progress has now been made with spray-cast perovskite PV devices recently demonstrated having a power conversion efficiency of 18.3%. We highlight trends within the research field and discuss challenges that will be necessary to drive such techniques toward practical application.
Light-Soaking-Free Inverted Polymer Solar Cells with an Efficiency of 10.5% by Compositional and Surface Modifications to a Low-Temperature-Processed TiO2 Electron-Transport Layer
Yu Yan, Feilong Cai, Liyan Yang, Jinghai Li, Yiwei Zhang, Fei Qin, Chuanxi Xiong, Yinhua Zhou, David G. Lidzey, Tao Wang Advanced Materials, Volume 29, January 4 2017, 1604044
Open Article: PCDTBT based solar cells: one year of operation under real-world conditions
Yiwei Zhang, Edward Bovill, James Kingsley, Alastair R. Buckley, HunanYi, Ahmed Iraqi, Tao Wang & David G. Lidzey Nature Scientific Reports, February 2016
Efficient planar heterojunction mixed-halide perovskite solar cells deposited via spray-deposition
Alexander T. Barrows, Andrew J. Pearson, Chan Kyu Kwak, Alan D. F. Dunbar, Alastair R. Buckley and David G. Lidzey Energy Environ. Sci., 2014, Volume 7, pages 2944-2950 (PDF compressed from original, 346kB)
Cover Article: Polymer Solar Cells: Fabricating High Performance, Donor–Acceptor Copolymer Solar Cells by Spray-Coating in Air
Tao Wang, Nicholas W. Scarratt, Hunan Yi, Alan D. F. Dunbar, Andrew J. Pearson, Darren C. Watters, Tom S. Glen,
Andrew C. Brook, James Kingsley, Alastair R. Buckley, Maximilian W. A. Skoda, Athene M. Donald, Richard A. L. Jones,
Ahmed Iraqi and David G. Lidzey Advanced Energy Materials, Volume 3, Issue 4, page 410, April 2013