2011 - 20th Annual NC State Undergraduate Research Spring Symposium

Two-dimensional chalcogenide nanosheets possess a great potential for important fields ranging from solar energy optoelectronics to superconducting.  However, efforts on controlled synthesis of the nanosheets have remained very limited.  Synthetic control is a necessary foundation for the nanosheet to be a useful material platform for both fundamental and applied interest.  We study the effect of substrates on the synthesis of tin selenide (SnSe₂) and germanium sulfide (GeS) by chemical vapor deposition. P(100)silicon (Si) and steam oxidized P(100) silicon (SiO₂) substrates are treated in piranha solution to cleanse and hydroxylate each substrate’s surface. The Si substrates are further treated with 5.0% HF to actuate hydrogen passivation of the surface. The deposition on the treated Si and SiO₂ surfaces were then characterized with scanning electron microscopy and raman scattering.  We found substantial differences in the deposition on the silicon and silicon oxide substrates.  We believe this is due to the different in surface energy  of the substrates.