Controllable preparation of silver nano-bowl coatings for suppressing secondary electron emission

•Ordered monolayer silver nano-bowl coatings prepared by an electrodeposition method.•Coating structure modulated by altering the deposition time and template diameter. Multipactor leads to the unrepairable damage to high-power microwave devices in the satellite. Restraining the secondary electron yield (SEY) is an effective method to suppress the multipactor of microwave devices. In this work, silver nano-bowl coating was fabricated via electrodeposition in AgNO3 electrolyte at room temperature on the surface of silver-plated aluminum alloy using the monolayer colloidal crystal of polystyrene (PS) spheres as templates. The scanning electron microscope images show that the surface structure of the silver-plated aluminum alloy sample could be modulated by altering the deposition time and adjusting the size of the PS spheres. And the pore diameter and the aspect ratio of the nano-bowl have a great influence on the SEY of the silver nano-bowl coating. When the size of the PS spheres is 2000 nm and the electrochemical deposition time is 90 min, the maximum value of SEY value of silver nano-bowl coating drastically decreases by 39.3% from 2.44 to 1.48, compared with that of the initial silver aluminum alloy samples. The silver nano-bowl coating shows great multipactor suppression for potential application in a satellite.