Abstract
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•We have simulated multiple-particle spray dynamics.•Characterizing the impact physics helps identify the optimum operating condition.•These simulations can be used to design coating method for low-cost CIGS solar cell.
High-speed spraying quickly deposits dry, solid particles at atmospheric pressure, without the use of binders, across large coating areas. We experimentally deposited Al2O3 and copper–indium–gallium–selenium (CIGS) nanoparticles on Al2O3 and molybdenum substrates and numerically replicated the results to elucidate the details of the deposition mechanisms. Thin films formed from layers of sprayed-particle impacts. Both single- and multiple-particle impacts are simulated and increases in pressure, temperature and von Mises stress are reported. Both experimentally and numerically, micron-sized particles are pulverized into flattened layers of nano-sized particle fragments. Characterizing the impact physics (particle collapse speed, energy exchange, and substrate damage) helps identify the optimum operating envelope for particle speeds less than 200m/s that maximizes thin-film growth rates and minimizes substrate damage.