Controlled faceting and morphology for light trapping in aluminum-catalyzed silicon nanostructures

• Published in: Journal of crystal growth Vol. 452; pp. 248 - 252
• Main Authors: Hainey, Mel F., Chen, Chen, Ke, Yue, Black, Marcie R., Redwing, Joan M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.10.2016
• Subjects: A1. Nanostructures; A3. Chemical vapor deposition processes; B1. Nanostructures; B2. Semiconducting silicon; B3. Solar Cells; A3. Chemical vapor deposition processes; A1. Nanostructures; B1. Nanostructures; B2. Semiconducting silicon; B3. Solar Cells
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2016.04.009

Aluminum-catalyzed silicon nanopyramids grown using low-pressure chemical vapor deposition (LPCVD) are presented as an approach to silicon surface texturing. The nanopyramids are grown by vapor-liquid-solid growth using aluminum thin films on silicon. Silicon nanowires with hexagonal cross-sections are formed at a growth temperature of 650°C; as the temperature is increased to 700°C, the wires become pyramid-shaped with triangular cross-sections. The silicon nanopyramids are single-crystal and grow in the direction with (112) facets, as confirmed by transmission electron microscopy. Pyramid tapering increases with increasing growth temperatures and the pyramid arrays grown at 700°C show reflectivities between 4 and 6% between 400nm and 800nm and appear black to the eye. Based on these results, aluminum-catalyzed nanopyramids present themselves as a plausible alternative to etch-based silicon surface textures. •Fabricated aluminum-catalyzed silicon nanowires and nanopyramids.•Transition from hexagonal wire to triangular pyramid with increasing temperature.•Reflectivities decrease with increased tapering.•Significant aluminum clustering and segregation occurring.