Periodic Reporting for period 1 - PerSiSTanCe (Low-cost and Large-Area Perovskite-Silicon Solar Tandem Cells)
Periodo di rendicontazione: 2019-05-01 al 2021-04-30
On the other hand, the main requirements in industry are low cost, high throughput and process reliability. Thus, production techniques and materials should be selected bearing in mind a compromise between cost reduction, acceptable efficiencies and process yield.
The aim of the project PerSiSTanCe (Low-cost and Large-Area Perovskite-Silicon Solar Tandem Cells) was producing large area and low cost perovskite tandem solar cells with industry friendly methods and materials, selected bearing in mind the most appropriate for their implementation in tandem Si/perovskite cells. The priority was the substitution of layers whose use would involve scarce/strategic materials or difficult and/or expensive processes. The result should be more robust and reliable processes and devices, contributing to reducing the gap between laboratory devices and the future mass production tandem cells.
Big steps have been given in this direction, all the components of the standard cell have been subject of analysis and optimization, resulting in a control standard device of around 21% efficiency. On the other hand, planar and inverted devices, the most favourable architecture for tandem devices was developed for the first time at the Adolphe Merkle Institute, achieving an efficiency of 17.4% thanks to a low cost solution processed nickel oxide hole transport layer, improved passivation interlayers and an optimized perovskite absorber. This result paves the way towards the in-house production of semi-transparent and perovskite-in-perovskite tandem devices.
The tasks fulfilled towards the achievement of the main objective have been:
- Protocols and methods for low cost hole transport materials like NiO have been developed and optimized.
- The sputter deposition protocols for ITO and indium-free (AZO) transparent conductive oxides have been developed and optimized.
- Deposition protocols for ZnO and SnO low cost inorganic electron transport layers developed.
- Planar and inverted perovskite solar cells were produced with high stabilities and efficiencies of up to 17.4%
- Successful perovskite deposition on industrial silicon textured substrates through Flash Infra-Red Annealing.
- Optimization of meso n-i-p control devices, achieving efficiencies of approximately 21%.
Part of these results have already been published in peer-reviewed publications and scientific conferences. There have been four publications with contributions from the current project, while there is an additional paper currently accepted, and two other manuscripts under preparation.
Regarding the conferences I participated with oral or graphical contributions in 4 of them, with a potential accumulated audience of hundreds to thousands of researchers.
The dissemination aspect of the grant was mainly focalized in local work within the City of Fribourg, with primary and secondary schools students taking part in simple solar energy expositions and laboratory practices. Through the workshops the students had the opportunity of not only getting in touch with solar and renewable energy specific aspects, but with science in general, giving them in many cases their first contact with how science is made.
The use of the Flash Infra-Red Annealing (FIRA) has allowed creating pseudo-conformal layers on texturized substrates. The combination of FIRA with an in-line solution process method like blade-coating, spray-coating or inkjet printing could result in an industrially feasible and vacuum-less method for Si/PSC tandems on texturized substrates. The specific conditions of perovskite solution molarity, substrate preparation and FIRA settings were optimized, the result is a uniform and conformal perovskite coating layer on texturized silicon, an achievement not out of reach for practically all the groups working on solution processing perovskite.