Colloidal-processed Si particle devices, device fabrication, and device uses have been presented. The generic device includes a substrate, a first electrode overlying the substrate, a second electrode overlying the substrate, laterally adjacent the first electrode, and separated from the first electrode by a spacing. A colloidal-processed Si particle layer overlies the first electrode, the second electrode, and the spacing between the electrodes. The Si particle layer includes a first plurality of nano-sized Si particles and a second plurality of micro-sized Si particles.