Researchers demonstrate a new method to fabricate solar perovskite solar cells in ambient air bringing their efficiency up to 18.3%, which could boost perovskite technology towards production and commercialization of high performance and stable devices.
Incredible progress has been made in Perovskite Solar Cells (PSCs) in the last 10 years, with their power conversion efficiency reaching up to 25.5%. Among the reported highly efficient devices, most were fabricated in a well-controlled inert environment.
However, large-scale manufacturing requires ambient processing, which affects the crystallization process of PSCs. Crystallization process in ambient air of PSCs has been widely discussed in literature, showing mostly how it is possible to deposit Perovskite Solar Cells (mainly MAPbI3) using Spin Coating process.
Castriotta et al. with the work entitled “Air-Processed Infrared-Annealed Printed Methylammonium-Free Perovskite Solar Cells and Modules Incorporating Potassium-Doped Graphene Oxide as an Interlayer”, published on ACS Applied Materials & Interfaces, conducted the work in order to develop an up-scalable technique for perovskite deposition processed in air and by using a Methyl Ammonium free perovskite, that is known as the most unstable cation in perovskite.
They were able to bring the efficiency up to 18.3% by air processing Cesium Formamidinium (CsFA) perovskite by applying potassium doped graphene oxide on top of the mesoporous layer and infrared annealing of the perovskite.
The fabricated devices showed an improved stability test compared to a standard multi cation perovskite fabricated in an inert atmosphere, with a T80 of 595h, 503h and 197 hours for shelf life, 85°C and light soaking tests, respectively.
Graphene interface engineering (GIE) and infrared (IR) treatment are proposed as two effective ways to boost PCE by limiting charge losses occurred at the perovskite/mTiO2 interface, enabling perovskite crystal formation in ambient environment.
In this work, by using a wide spectrum of characterization techniques, the authors demonstrate that it is possible to fabricate CsFA based perovskite out of the glovebox through the combined effect of interface engineering of GO-K on mesoporous layer and infrared annealing of the perovskite layer.
The fine-tuning of GO-K and infrared annealing have a strong impact on the cell and modules’ performance in terms of efficiency and stability.
These results, obtained in ambient conditions, pave the way towards industrialization of PSC-based photovoltaic technology.
This outstanding result has been conducted thanks to a joint European effort and collaboration between different research centres and institutes, as listed below:
- University of Rome Tor Vergata, Centre for Hybrid and Organic Solar Energy (C.H.O.S.E.), Department of Electronic Engineering.
- Istituto Italiano di Tecnologia, Centre for Nano Science and Technology (CNST@PoliMi).
- Polytechnic University of Milan, Department of Physics.
- Istituto di Struttura della Materia (ISM-CNR).
- Cicci Research s.r.l.
- Technische Universität Dresden, Dresden Center for Nanoanalysis (DCN), Center for Advancing Electronics Dresden (cfAED).
- National University of Science and Technology MISiS, Laboratory for Advanced Solar Energy (LASE).
- Hellenic Mediterranean University, Department of Electrical and Computer Engineering.
Luigi Angelo Castriotta
Centre for Hybrid and Organic Solar Energy (C.H.O.S.E.)
Tor Vergata University of Rome
News release provided by the Centre for Hybrid and Organic Solar Energy (C.H.O.S.E.).