We present two distinct methods to nanostructure the surface of amorphous silicon to produce unique, nanoscale surface features. One method is a dry etch process that employs a modified Bosch1 process on an advanced silicon etcher to produce needle-like features of amorphous silicon. Likewise, we also investigated metal-assisted wet chemical etching2 as an alternative method to nanostructure the amorphous silicon to produce porous-like features. The resulting surface topography leads to an optically black appearance over patterned or large areas. This is a result of the interspacing between each needle and pore that leads to a high optical absorption. Thus, we designate it as black amorphous silicon (b-a-Si). We have deposited and formed regions of b-a-Si on variety of insulating films and metal electrodes, including chrome and titanium. In this study, we characterize the electrical and optical properties of as-deposited amorphous silicon and nanostructured amorphous silicon.