NOVELTY - Matrix with at least one embedded array of nanowires, comprises nanowires, each of the nanowires including a first end and a second end; and one or more fill materials located between the nanowires; where the nanowires are substantially parallel to each other and are fixed in position relative to each other by one or more fill materials; each of one or more fill materials is associated with a thermal conductivity less than 50 Watts per meter per degree Kelvin; and the matrix is associated with at least a sublimation temperature and a melting temperature.    USE - The matrix is useful in solar power, battery electrodes and/or energy storage, catalysis, and/or light emitting diodes.    ADVANTAGE - The invention forms arrays of nanostructures from materials with advantageous electrical, thermal, and mechanical properties for use in thermoelectric devices.    DETAILED DESCRIPTION - Matrix with at least one embedded array of nanowires, comprises nanowires, each of the nanowires including a first end and a second end; and one or more fill materials located between the nanowires; where the nanowires are substantially parallel to each other and are fixed in position relative to each other by one or more fill materials; each of one or more fill materials is associated with a thermal conductivity less than 50 Watts per meter per degree Kelvin; and the matrix is associated with at least a sublimation temperature and a melting temperature, the sublimation temperature and the melting temperature each being above 350 degrees C; or matrix with at least one embedded array of nanostructures, comprises nanostructures including first ends and second ends respectively, the nanostructures corresponding to voids; and one or more fill materials located at least within the voids; where each of the nanostructures includes a semiconductor material; the nanostructures are substantially parallel to each other and are fixed in position relative to each other by one or more fill materials; each of one or more fill materials is associated with a thermal conductivity less than 50 Watts per meter per degree Kelvin; and the matrix is associated with at least a sublimation temperature and a melting temperature, the sublimation temperature and the melting temperature each being above 350 degrees C. An INDEPENDENT CLAIM is a method for making a matrix with at least one embedded array of nanostructures, comprising filling voids corresponding to nanostructures with at least one or more fill materials, each of one or more fill materials being associated with a thermal conductivity less than 50 Watts per meter per degree Kelvin, the nanostructures including a semiconductor material; and forming a matrix embedded with at least the nanostructures, the matrix being associated with at least a sublimation temperature and a melting temperature, the sublimation temperature and the melting temperature each being above 350 degrees C; where the process for filling the voids includes keeping the nanostructures substantially parallel to each other; and fixing the nanostructures in position relative to each other by one or more fill materials.