Analysis of crystalline phases and integration modelling of charge quenching yields in hybrid lead halide perovskite solar cell materials. (October 2017)

• Record Type: Journal Article
• Authors: Park, Byung-wook; Zhang, Xiaoliang; Johansson, Erik M.J.; Hagfeldt, Anders; Boschloo, Gerrit; Seok, Sang Il; Edvinsson, Tomas
• Is Part Of: Nano energy. Volume 40(2017:Oct.)
• Page Start: 596
• Page End: 606
• Publication Date: 2017-10
• Subjects: Charge quenching yield -- Photoluminescence -- Band gap grading -- Hybrid perovskite solar cells -- Cl inclusion effect; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2017.08.055
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Organic inorganic metal halide perovskites (OIHPs) has emerged as promising photovoltaic materials the latest years. Many OIHPs, however, have complex material compositions with mixed cation and halide compositions, phase mixtures, as well as beneficial remains of PbI2 in the final solar cell materials where the complex material composition with dual conduction and valence band states and its effects on the performance remain unclear. Here, we report an approach to analyze the phase mixture, order-disorder phases and the emissive electronic states via a 4-state model of the photoluminescence yield. The approach is applied to scaffold layer perovskite materials with different mixed halide composition. The optical transitions and the full emission spectra are de-convoluted to quantify the band gaps and charge quenching yields in the OIHPs. An approach to extract the excited state coupling parameters within the 4-state model is also briefly given. The integration model is finally utilized in charge quenching yield analysis for the different materials and correlated with solar cell performance from MAPbI3 and MAPbI3−x Clx in mesoporous TiO2 layers where inclusion of Cl improves crystal formation and is compared to alternative approaches using optimized solvents and anti-solvent methods. A band gap grading effect was found to be present for the scaffold MAPbI3 and increased for MAPbI3−x Clx, beneficial for decreased hole concentration at the back contact and thus reducing back contact recombination. Graphical abstract: An approach to analyze the structural order-disorder phases and the emissive electronic states via a 4-state model of the photoluminescence yield is presented. Charge quenching yield analysis of mixed halide perovskite materials correlate well with the solar cell performance from MAPbI3 and MAPbI3−x Clx in mesoporous TiO2 layers where a band gap grading effect was found, beneficial for suppressing back-contact recombination. Highlights: Analysis of structural order-disorder and the emissive electronic states via a 4-state model is presented. Charge quenching yield analysis of mixed halide perovskite materials. Crystallization behavior of Cl inclusion in MAPbI3−x Clx is compared with low and high oxidation conditions in MAPbI3 . Efficiencies of 13.1% and 15.5% are obtained for Cl-inclusion and up to 18.2% for MAPbI3 using anti-solvent treatment. A band gap grading effect was found for the scaffold MAPbI3 and MAPbI3-x Clx, devices not present for the planar system.