Progression towards high efficiency perovskite solar cells via optimisation of the front electrode and blocking layer

Yates, HM; Afzaal, M; Walter, A; Hodgkinson, JL; Moon, S-J; Sacchetto, D; Brauninger, M; Niesen, B; Nicolay, S; McCarthy, M; Pemble, ME; Povey, IM; Ballif, C

Abstract

The effects of fluorine doped tin oxide (FTO) electrode, titanium dioxide (TiO2-x) blocking layer (BL) and perovskite (methyl ammonium lead triiodide) preparation on the overall properties of the photovoltaic cells have been studied. The FTO electrode was deposited by atmospheric pressure chemical vapour deposition (APCVD) and the hole blocking layer by spin coating, atomic layer deposition (ALD) or sputtering. We have shown the importance of obtaining uniform thin films of FTO, with low sheet resistance to aid the formation of pin hole free uniform TiO2-x blocking layers and hence well adhered, perovskite layers. Optimal BL thickness was 20 nm, while thicker films gave decreased shunt resistance and a greater number of pin holes through the layers. We also showed that the conformal nature of ALD and magnetron sputtering, along with their increased uniformity control over spin coating again improved cell efficiency. The main improvement comes for the smaller Roc, attributed to an improved electrical transport through particularly the sputtered TiO2-x blocking layer. After identifying the optimised parameters, all the properties were combined to fabricate large solar cells (1 cm2) yielding power conversion efficiencies beyond 16%.

Citation

Yates, H., Afzaal, M., Walter, A., Hodgkinson, J., Moon, S., Sacchetto, D., …Ballif, C. (2016). Progression towards high efficiency perovskite solar cells via optimisation of the front electrode and blocking layer. Journal of Materials Chemistry C, 4(47), 11269-11277. https://doi.org/10.1039/C6TC04647A

• Journal Article Type: Article
• Acceptance Date: Nov 14, 2016
• Online Publication Date: Nov 14, 2016
• Publication Date: Nov 14, 2016
• Deposit Date: Jan 20, 2017
• Publicly Available Date: Nov 14, 2017
• Journal: Journal of Materials Chemistry C
• Print ISSN: 2050-7526
• Publisher: Royal Society of Chemistry
• Volume: 4
• Issue: 47
• Pages: 11269-11277
• DOI: https://doi.org/10.1039/C6TC04647A
• Publisher URL: http://dx.doi.org/10.1039/C6TC04647A
• Related Public URLs: http://pubs.rsc.org/en/journals/journalissues/tc#!recentarticles&adv
• Additional Information: Funders : EU; Projects : Process line implementation for applied surface nanotechnologies; Grant Number: FP7 NMP.2012.1.4-1 309530