In situ X-ray scattering of perovskite solar cell active layers roll-to-roll coated on flexible substrates. Issue 27 (10th June 2016)

• Record Type: Journal Article
• Authors: Rossander, Lea H.; Larsen-Olsen, Thue T.; Dam, Henrik F.; Schmidt, Thomas M.; Corazza, Michael; Norrman, Kion; Rajkovic, Ivan; Andreasen, Jens W.; Krebs, Frederik C.
• Is Part Of: CrystEngComm. Volume 18:Issue 27(2016)
• Page Start: 5083
• Page End: 5088
• Publication Date: 2016-06-10
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/c6ce00382f
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : Drying and crystal growth kinetics are key to high performance of perovskite solar cells and are efficiently studied using in situ synchrotron based X-ray probing while slot-die coating on flexible substrate machine. Abstract : In an effort to understand recent results showing differences between the power conversion efficiencies of lead halide (CH3 NH3 PbI3− x Cl x ) solar cells on glass versus flexible substrates, this study investigates the influence that substrate and processing methods have on morphological and crystallographic development. Using our in situ slot-die micro roll-to-roll coater setup, we measured small and wide angle X-ray scattering in grazing incidence while the material dried, enabling us to follow the crystallization from just after the deposition and up to 25 minutes later. The data showed differing crystallographic developments between the substrates, especially seen through the behaviour of a crystalline precursor which survived longer on the flexible substrates than on glass. Additionally, the common degradation product PbI2 was absent on the thickest flexible substrate. This leads us to conjecture that the flexible substrates absorb part of the solvent, thereby delaying evaporation and changing the solvent environment around the perovskite. As a further test, we produced solar cells with the same substrates and confirmed that the ones made on flexible substrates performed worse than those made on glass, but that when including an ITO layer in the stack it seemed to act as a buffer, whereby the solar cell performance was improved.