In-induced variation in the electronic structure of in/si(001)4 × 3 nanoclusters

We present our first-principles total-energy calculations on electronic structure of the In/Si(001)4 × 3 nanoclusters as the In doping changes. At an In coverage of 0.5 ML, the magic nanocluster Siylne is semiconducting with a band gap of 0.54 eV. There are two different experimental results for the further In-doped cluster: One is metallic [Kotlyar et al., Phys. Rev. Lett. 91, 026104 (2003)] and the other is semiconducting [Ahn et al., Phys. Rev. B, 70, 113304 (2004)]. Based on the formation energy and the band structure calculations, we suggest that both the metallic (Si ₆In ₇) and the semiconducting (Si ₅In ₈) clusters can appear, depending on the experimental conditions, which can explain the different electronic properties between the experiments by Kotlyar et al. and by Ahn et al.