Hierarchically structured porous cadmium selenide polycrystals using polystyrene bilayer templates

In this study, a novel approach is demonstrated to fabricate hierarchically structured cadmium selenide (CdSe) layers with size-tunable nano/microporous morphologies achieved using polystyrene (PS) bilayered templates (top layer: colloidal template) via potentiostatic electrochemical deposition. The PS bilayer template is made in two steps. First, various PS patterns (stripes, ellipsoids, and circles) are prepared as the bottom layers through imprint lithography. In a second step, a top template is deposited that consists of a self-assembled layer of colloidal 2D packed PS particles. Electrochemical growth of CdSe crystals in the voids and selective removal of the PS bilayered templates give rise to hierarchically patterned 2D hexagonal porous CdSe structures. This simple and facile technique provides various unconventional porous CdSe films, arising from the effect of the PS bottom templates.