Self Assembled Nanocluster Based Photo Detectors

This Navy Phase I SBIR program would develop self assembled nanocluster based photo detector devices, using NanoSonic's patented new process - molecular level self-assembly performed at room temperature. Specifically, we would combine advances in the nanocluster materials, with electrostatic self-assembly (ESA) processes, to enable large-area, low-cost device manufacturing on rigid and flexible substrates. Such a molecular-level self-assembly approach to form photo detector devices and materials offers advantages over conventional processes, in that very different materials can be incorporated uniformly using the same chemical process at room temperature. During this program, NanoSonic will focus on improving the efficiency of the photo detectors via the following four areas: 1) higher light collection efficiency, 2) higher charge separation efficiency, 3) higher charge transportation efficiency and 4) broadband tandem configuration. We will work on a variation of material properties such as photovoltaics, photoconductivity and photodielectrics and achieve an optical antenna. Nanocluster scatterers may be self-assembled into the detector material to increase local photon interaction, and photonic crystal structure would be incorporated to provide light trapping or steering or to alter the polarization of the incident light. Potentially metal nanoclusters fabricated by NanoSonic can be utilized as a means of achieving surface plasmon resonance increases in energy harvesting. We will consider forming heterostructures using NCs such as CdTe, CdSe, PbS, and PbSe with other semiconductor materials of higher mobility, such as porous silicon (pSi), amorphous silicon (a:Si) and nanocrystalline silicon (nc:Si) to reduce the carrier recombination. We will also investigate the heterogeneous selections of nanocrystals to form a multi-heterojunctioned tandem photodetector device to fully use spectrum of interest. In addition, NanoSonic0304s QD-PMMA composite may be used to fabricate the top films of the photodetector devices as down-converters to shift the incident high-energy photons toward lower energies for which the photodetectors work more efficiently. NanoSonic will experimentally validate nanocluster based photodetector performance through extended field test evaluation, and possible testing with Lockheed Martin, and produce first-generation QD photodetecors and systems for sale.