Layer‐By‐Layer Printed Metal Hybrid (Cs:FA)PbI₃ Perovskite Nanocrystal Solar Cells

Abstract

Mixed halide perovskite nanocrystals in the form of cesium/formamidinium lead triiodide ((Cs:FA)PbI3) offer great potential for efficient and stable solar cells. To date, large‐scale production with roll‐to‐roll compatible deposition methods remains difficult and requires detailed research on each involved processing step. Here, a proof‐of‐concept study about slot‐die coating (printing) the active layer of (Cs:FA)PbI3‐based nanocrystal solar cells is presented. Structural and morphological changes during ligand exchange of long‐chain oleic acid and oleylamine by Pb(NO3)2, and top‐layer FAI passivation are investigated. Ligand exchange improves the processability of the nanocrystal layer and enhances charge transport. It also changes texture from face‐on toward edge‐on orientation as grazing‐incidence X‐ray scattering studies indicate. Ligand exchange and FAI passivation redshift photoluminescence and prolong charge carrier lifetime in the printed nanocrystal films. The proof‐of‐concept feasibility of printing metal halide perovskite nanocrystal films for solar cells is shown by building 20 devices with a median power conversion efficiency of 6.39%.

INSIGHT: in situ heuristic tool for the efficient reduction of grazing-incidence X-ray scattering data

“…Sun et al (2023) investigated the degradation in CsI bulk-modified perovskite materials and identified water-induced volume expansion and morphology changes by GISAXS/GIWAXS measurements. Recently, GIWAXS indexing using INSIGHT revealed changing quantum dot orientations during thin-film deposition and processing and showed the importance of carefully tuning each processing step (Reus et al, 2023).…”

“…The respective variation parameters for G hkl (radial broadening) and � (azimuthal broadening) are shown in Table 3. Recently, indexing of perovskite nanocrystal GIWAXS data using INSIGHT was reported (Reus et al, 2023) and this is discussed in Section 7.…”

“…INSIGHT has been used in multiple publications over the last two years, spanning material classes from organic polymer thin films to perovskite nanocrystal thin films (Reus et al, 2022;Grott et al, 2022;Li, Guo et al, 2022;Ye et al, 2022;Heindl et al, 2022;Reb et al, 2023;Sun et al, 2023;Reus et al, 2023). In this section, four publications that used INSIGHT for 2D GISAXS/GIWAXS data are briefly introduced to demonstrate the diverse application range.…”

“…Bragg spot indexing with INSIGHT was used to follow the orientational changes of perovskite quantum dots (QDs) during the processing steps of creating the absorber layer of a solar cell (Reus et al, 2023). Three different QD layer configurations were investigated and the corresponding GIWAXS images with indexing are shown in Fig.…”