The addition of Ag nanoclusters to a semiconductor surface creates long lived localized electronic excitations that increase the overall photoconductivity of the system by preventing charge carrier recombination (R. Hembree and D. A. Micha, J. Chem. Phys. 138, 184708 (2013)). Starting from the atomic structure of the materials, it is shown how measurable properties of absorbance and photomobility can be calculated from ab initio energy  bands and orbitals generated from GGA and hybrid density functionals in a plane wave basis, for models of Si slabs involving large atomic supercells (T. Vazhappilly and D. A. Micha, J. Phys. Chem. C 118, 4429 (2014)). Properties are calculated using the equations of motion of a reduced density matrix (RDM), generating steady state solutions for the RDM in the presence of light and relaxation due to phonons and excitons. This is used in calculations of the electron and hole photomobility for varying visible light wavelength in crystalline Si slabs without and with adsorbed metal clusters of Ag. It shows that the adsorbates increase light absorption at low photon energies and also increase electronic currents, and explains the underlying mechanism. The present treatment extends our previous work on optical properties of crystalline and amorphous Si slabs which have provided results in good agreement with experimental measurements on amorphous Si.* Work partly supported by the Chemistry Division of the National Science Foundation of the USA, and by the Dreyfus Foundation

Electron and hole photomobilities at a semiconductor surface with adsorbed metal clusters: Atomic modeling relevant to experimental measurements

248th National Meeting (2014)

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