Perovskite Solar Cell Fabrication: We used the same perovskite fabrication technique for both films and solar devices. Pre-cut and commercially pre-patterned ITO-coated soda lime glass substrates (Latech, 10 Ω cm -2 ) were cleaned in sequence by sonication in: Milli-Q water (10 minutes at 25 °C), 2% Hellmanex® solution (10 minutes at 25 °C), acetone (10 minutes at 40 °C), isopropanol (15 minutes at 40 °C), ethanol (10 minutes at 25 °C). The substrates were subsequently treated with oxygen plasma for 12 minutes. We then fabricated ligand-modified NiO films employing method developed by Michalska and Surmiak et al. Subsequentially, such prepared substrates with NiO films were transported to the glovebox with the system; they were then preheated on hot plate at 100 °C for 30 minutes and the N2 was constantly applied onto the hot-plate area to remove residual H2O. After that the substrates were brought to deposition pre-set temperature on programmable hot-plate stage. The precursor solution was pushed through the ultrasonic piezoelectric microfluidic device (see Supporting Information for more details) by programmable syringe pump (Chemyx 4000); the purity of the composition is ensured by emptying the dead volume from tubes (at least 3 times the tube length of 20 cm) into the purging waste container. Each pre-heated substrate located inside the cavity was blown with N2 gas to remove any residual particles directly prior the deposition. Aliquots of 6 µL of perovskite precursor solution were deposited on the substrate and 10 seconds was allowed for the precursor solution to spread across the surface prior to quenching with an applied N2 gas stream. The hot-plate was subsequently heated up to chosen annealing temperature, with the temperature maintained for 60 minutes, followed by cooling of the films naturally to RT.