Epitaxial Metal Halide Perovskites by Inkjet‐Printing on Various Substrates

Abstract

Metal-halide-perovskites revolutionized the field of thin-film semiconductor technology, due to their favorable optoelectronic properties and facile solution processing. Further improvements of perovskite thin-film devices require structural coherence on the atomic scale. Such perfection is achieved by epitaxial growth, a method that is based on the use of high-end deposition chambers. Here epitaxial growth is enabled via a ≈1000 times cheaper device, a single nozzle inkjet printer. By printing, single-crystal micro-and nanostructure arrays and crystalline coherent thin films are obtained on selected substrates. The hetero-epitaxial structures of methylammonium PbBr 3 grown on lattice matching substrates exhibit similar luminescence as bulk single crystals, but the crystals phase transitions are shifted to lower temperatures, indicating a structural stabilization due to interfacial lattice anchoring by the substrates. Thus, the inkjet-printing of metal-halide perovskites provides improved material characteristics in a highly economical way, as a future cheap competitor to the high-end semiconductor growth technologies.

Inkjet Printing Epitaxial Metal Halide Perovskites on Various Substrates?

“…Sytnyk et al. [ 1 ] claimed to be able to print epitaxial MAPbBr 3 microcubes on (001)PbS. This claim means the formation of at least semi‐coherent interfaces with the epitaxial relationship of (001)MAPbBr 3 ∥(001)PbS and [100]MAPbBr 3 ∥[100]PbS.…”

“…Based on the COM image of Figure 1b (bottom) and/or the SEM images of Figures S6 and S1 in ref. [ 1 ] , instead, Sytnyk et al. [ 1 ] drew the conclusion that faceted MAPbBr 3 microstructure arrays are grown whose side edges are aligned in respect to the {100} cleaved planes of the PbS substrate.…”

“…[ 1 ] , instead, Sytnyk et al. [ 1 ] drew the conclusion that faceted MAPbBr 3 microstructure arrays are grown whose side edges are aligned in respect to the {100} cleaved planes of the PbS substrate. Then they claimed that the single‐crystal MAPbBr 3 microcubes exhibit an epitaxial relationship with the (001)PbS substrate.…”

“…More inconceivably, they stated that the running directions of cracks, shown in the SEM image of Figure S5 in ref. [ 1 ] , evidence the epitaxial nature of a ≈300‐nm‐thick MAPbBr 3 film on (001)PbS. However, both SEM and COM are morphology characterization techniques.…”

“…Sytnyk et al. [ 1 ] claimed the epitaxial growth of the archetypical MHPs, CH 3 NH 3 PbBr 3 , CH 3 NH 3 PbI 3 , (CH 3 NH 3 = methyl ammonium, MA), CsPbBr 3 , and CsPbCl 3 by inkjet printing, and they reported that single‐crystal micro‐ and nanostructure arrays as well as crystalline coherent thin films were obtained on selected substrates, see Table 1 . There appear to be errors in methodology for verifying epitaxy.…”