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4Lead halide perovskite micro-optics fabrication by femtosecond laser ablation
A. Cherepakhin1*, A. Zhizhchenko12, A. Porfirev3, A. Pushkarev4, S. Makarov4, A. Kuchmizhak1
1-Institute of Automation and Control Processes, Far Eastern Branch of RAS, Vladivostok 690061, Russia 2- Far Eastern Federal University, Vladivostok 690061, Russia 3- Image Processing Systems Institute of the RAS-Branch of FSRC "Crystallography & Photonics " of the RAS,
Samara 443001, Russia 4- ITMO University, St. Petersburg, Russia, 197101
In this work, by applying method of direct imprinting using single-pulse fs-laser projection lithography we demonstrate fabrication of optical-quality micro-scale Fresnel zone plates (FZP) for generation of focused laser beam, as well as binary fork-shaped gratings (FSGs) and binary spiral micro-axicons which allow generation of vortex beams in reflection mode on a surface of chemically synthesized CsPbBr3 perovskite microcrystals. The achieved ultra-smooth ablation of perovskite microcrystals was explained by ultrafast laser-induced thermalization rate as well as extremely low conductivity of the CsPbBr3 material. These findings highlight the potential of CsPbBr3 microcrystals to be a promising material for the realization of intricate 2D micro-optical elements and holograms, directly imprinted using non-destructive and practically relevant laser technologies.
Figure 1. (a) Schematic illustration of the setup for fs-laser projection lithography. (b) Design of the amplitude masks used to generate intensity patterns for laser printing of the FZP, spiral microaxicons and fork-shaped gratings. (c) Top-view SEM images of the CsPbBr3 microcrystal surface imprinted with various micro-optical elements including FZP, binary spiral axicons (b,c) and binary fork-shape grating (d) of the as well as corresponding focal-plane intensity distributions at 515 nm excitation wavelength showing focusing performance of the imprinted 2D perovskite micro-optics.
The excellent performance of the imprinted micro-optics demonstrates the suitability of fs-laser projection lithography for the direct fabrication of various functional elements and devices. The lateral resolution of fs-laser ablation at 515 nm on CsPbBr3 can achieve 250-300 nm. This high resolution is generally attributed to the material's extremely low thermal conductivity, two orders of magnitude lower than that of silicon and its exceptionally fast thermalization rate upon laser exposure. The sub-picosecond timescale of CsPbBr3 thermalization, facilitated by Auger recombination of photo-excited carriers effectively minimizes the heat-affected zone.
This work was supported by Russian Science Foundation (grant. 24-79-10271).
