Abstract: A materials structure is presented which is based on the insertion of preformed nanocrystals of arbitrary shape on or into a non-crystalline, non-hydrocarbon barrier layer. Embodiments of the structure include a variety of barrier layers and contacts, which can be layered. When the structure is used as a detector or a solar cell, transport of charged carriers created in the nanocrystals during the absorption process occurs through quantum mechanical tunneling, thermionic emission or diffusion to electronic contacts. One embodiment of such a structure is a photovoltaic device, where a built-in bias is established using different contact materials and barrier layers. The structure can also be used as a modulator or emitter. The invention may consist of many structures stacked and sharing adjacent contact regions, where individual layers are tuned to absorb, emit or modulate light at a specific frequency or groups of frequencies.