HIGH-DENSITY ARRAY OF SIZE-CONTROLLED SILICON NANODOTS FOR ALL SI SOLAR CELLS

摘要

Silicon quantum dots and crystalline silicon heteroface structure is investigated. Nucleation of the quantumdots was achieved by implanting Si~+ ions into SiO_2 films, thermally grown on a Si(100) substrate. A multipleimplantation step was used to obtain homogenous distribution of quantum dots in the SiO2 matrix The thickness of theoxide layer, the stoichiometry of the implanted layer, and the depth profiles of the implanted ions were determined byboth Rutherford backscattering spectroscopy and ellipsometry techniques. Characterization by transmission electronmicroscopy indicates that the diameter of the silicon quantum dots varies from 2 to 20 nm, which is in the range of theBohr 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 improvementsto the third generation solar cells.