An optoelectronic device, such as a
solar cell, light-emitting device, or
photodetector, comprises a substrate, a number of fibers supported by the substrate so that an end of each
fiber is in electrical communication with the
substrate surface; an optional first layer, covering the substrate, though which the fibers protrude, and a second layer overlaid on at least part of the first layer and exposed
fiber surfaces. The second layer may be electrically conducting, and electrically isolated from the
substrate surface by the first layer. The second layer can be in electrical communication with each
fiber, and an electrically conducting path can exists between the second layer and the
substrate surface through each fiber. The substrate, in whole or in part (such as the substrate surface) can be electrically conducting. The electrically conducting path may comprises a
semiconductor p-n junction, so that the optoelectronic device emits light, provides a photovoltaic potential, and / or is sensitive to light, for example acting as a
photoresistor,
photodetector, and the like.