design and optimization of novel zns–metal core-shell random structures for light harvesting—a computational study

We present a systematic computational study on the optical properties of a new composite structure based on zns–metal core-shell particles, which can find applications in light trapping. three metals au, ag and cu whose surface plasmon resonance (spr) fall in visible region are used as shell materials. effect of shell material, thickness and core radius on the spr values is studied using mie theory. optimization of aspect ratios for each composite is done for maximum extinction in visible region. uniform random distribution of selected particles with optimized aspect ratios is modelled using lumerical fdtd software. transmission of wavelengths 400, 450, 500, 550, 600 and 650 nm through random media is investigated using finite difference time domain simulations. shell material is found to have a large influence on light trapping ability of the composite. depending on the shell material, thickness and core radius, wavelengths at different regions of visible spectrum can be trapped, thus offering scope for designing novel light harvesting systems tunable over specific wavelength regions.