Fabrication of wafer-scale polystyrene photonic crystal multilayers via the layer-by-layer scooping transfer technique

This paper reports on a simple synthetic method for fabricating a wafer-scale colloidal crystal film of 2D crystals in a 1D stack based on a combination of two simple processes: the self-assembly of polystyrene (PS) nanospheres at the water-air interface and the layer-by-layer (LbL) scooping transfer technique. This method can routinely fabricate photonic crystal (PhC) multilayers over 4 inch diameter wafers with a controllable number of layers and vertically crack-free over wafer-scale area. We investigate the optical and morphological properties of the PhC multilayers fabricated using various mono-sized colloidal crystals (250, 300, 350, 420, 580, 720, and 850 nm), and mixed binary colloidal crystals (300/350 and 250/350 nm).