High-Resolution In Situ Crystallization and Patterning of a CsPbBr₃ Film via Femtosecond Laser Printing

Abstract

Establishing high-precision patterning technology for high-quality perovskite films is critical for practical applications requiring optoelectronic device arrays. Here, we report a femtosecond laser printing strategy to realize high-precision and high-quality patterned perovskite films by integrating in situ crystallization and patterning in one printing step. Compared with a thermal-annealed CsPbBr 3 film, the crystallization quality of a laser-printed film has been improved because of localized nucleation and growth at the laser-irradiated area, avoiding the incomplete film coverage and poor crystallization quality due to rapid solvent evaporation in the large area during the thermal annealing process. Also, high-resolution pixel arrays and designed patterns with a minimum line width of 2 μm have been demonstrated by means of the high precision of femtosecond laser printing. More importantly, we have fabricated a prototype of perovskite light-emitting diodes (LEDs) demonstrating the potential of femtosecond laser printing technology for the fabrication of high-precision patterned perovskite film optoelectronic devices for display application.

Laser Technology for Perovskite: Fabrication and Applications

“…Reproduced with permission. [108] Copyright 2023, American Chemical Society. f) Schematic illustration of focusing transmitted light into a 3D spot through a designed 2D perovskite flat lens with concentric rings structure; f is focal length, 𝛽 is convergence angle, and k is wave vector.…”

“…Liang et al integrated in situ crystallization and patterning of CsPbBr 3 perovskite films in one fs laser printing step. [108] Laser printing can improve the crystallization quality of perovskite film owing to the localized nucleation and growth and simultaneously achieve high-resolution patterning with a minimum line width of 2 μm (Figure 8c-e). Liang et al demonstrated a fs laser regulatory focus patterning technique and fabricated an annular line of 200 nm width of perovskite film by adjusting the laser focus depths.…”