Luminescence properties of a cubic silicon cluster octasilacubane

We have studied the luminescence properties of a Si₈ cubic cluster, octasilacubane. The photoluminescence (PL) is observed around 1.7 eV at low temperatures and the PL decay is a single exponential with a time constant of 3.1 ms. The PL intensity and the PL lifetime abruptly decrease with increasing temperature above 40 K. The PL properties are strongly affected by nonradiative recombination processes. The luminescence properties of the cubic Si₈ cluster are different from those of the chain and ladder Si₈ clusters. The optical properties of the cubic cluster are discussed.