Structural and Optical Properties of Oxygenated Silicon Quantum Dots

Silicon quantum dots of size as small as 1 nm in diameter were prepared by wet chemical route. These clusters are found to be covered with oxygen and hydrocarbon molecules. The optical measurements reveal strong absorption around 4.67 eV and weak absorption at lower energies. The clusters show a broad luminescence around 3.87 eV. These quantum dots are modeled using ab-initio Car Parinello Molecular Dynamics and computational studies explain the absorption spectrum of the clusters over observed energy range. In principle, these quantum dots can be useful as scintillating layer on crystalline silicon solar cells to enhance the photovoltaic efficiency.