Drying Dynamics of Solution‐Processed Perovskite Thin‐Film Photovoltaics: In Situ Characterization, Modeling, and Process Control. Issue 39 (27th August 2019)

• Record Type: Journal Article
• Authors: Ternes, Simon; Börnhorst, Tobias; Schwenzer, Jonas A.; Hossain, Ihteaz M.; Abzieher, Tobias; Mehlmann, Waldemar; Lemmer, Uli; Scharfer, Philip; Schabel, Wilhelm; Richards, Bryce S.; Paetzold, Ulrich W.
• Is Part Of: Advanced energy materials. Volume 9:Issue 39(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-08-27
• Subjects: blade coating -- crystallization -- drying control -- in situ -- perovskite solar cells; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201901581
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: A key challenge for the commercialization of perovskite photovoltaics is the transfer of high‐quality spin coated perovskite thin‐films toward applying industry‐scale thin‐film deposition techniques, such as slot‐die coating, spray coating, screen printing, or inkjet printing. Due to the complexity of the formation of polycrystalline perovskite thin‐films from the precursor solution, efficient strategies for process transfer require advancing the understanding of the involved dynamic processes. This work investigates the fundamental interrelation between the drying dynamics of the precursor solution thin‐film and the quality of the blade coated polycrystalline perovskite thin‐films. Precisely defined drying conditions are established using a temperature‐stabilized drying channel purged with a laminar flow of dry air. The dedicated channel is equipped with laser reflectometry at multiple probing positions, allowing for in situ monitoring of the perovskite solution thin‐film thickness during the drying process. Based on the drying dynamics as measured at varying drying parameters, namely at varying temperature and laminar air flow velocity, a quantitative model on the drying of perovskite thin‐films is derived. This model enables process transfer to industry‐scale deposition systems beyond brute force optimization. Via this approach, homogeneous and pinhole‐free blade coated perovskite thin‐films are fabricated, demonstrating high power conversion efficiencies of up to 19.5% (17.3% stabilized) in perovskite solar cells. Abstract : For enabling efficient scale‐up strategies in the field of perovskite photovoltaics, this work demonstrates general, quantitative modeling of the precursor thin‐film thickness evolution by controlling the drying process by a laminar air flow with simultaneous laser reflectometry. The model presented here enables the prediction of the perovskite thin‐film morphology for arbitrary dryers—yielding homogeneous perovskite absorber layers fabricated by blade coating.