High density array of size controlled silicon nanodots for all Si solar cells

Abstract

Silicon quantum dots and crystalline silicon heteroface structure is investigated. Nucleation of the quantum dots was achieved by implanting Si ions into SiO2 films, thermally grown on a Si(100) substrate. A multiple implantation step was used to obtain homogenous distribution of quantum dots in the SiO2 matrix The thickness of the oxide layer, the stoichiometry of the implanted layer, and the depth profiles of the implanted ions were determined by both Rutherford backscattering spectroscopy and ellipsometry techniques. Characterization by transmission electron microscopy indicates that the diameter of the silicon quantum dots varies from 2 to 20 nm, which is in the range of the Bohr radius of bulk crystalline Silicon (5 nm). Electrical properties have been investigated I-V and C-V measurements. Despite the weak efficiency of these devices, these results remain very promising and offer potentially vast improvements to the third generation solar cells.