Title :
Growth of epitaxial quality SnS thin films on graphene
Author :
Wang, W. ; Leung, Kin K. ; Fong, W.K. ; Wang, S.F. ; Hui, Y.Y. ; Lau, S.P. ; Surya, Charles
Author_Institution :
Dept. of Electron. & Inf. Eng., Hong Kong Polytech. Univ., Hong Kong, China
Abstract :
SnS van der Waals epitaxies (vdWEs) were grown by molecular beam epitaxy (MBE) on layered substrates such as graphene and mica. Photo-absorption measurements indicate an indirect bandgap of ~1 eV and a direct bandgap of ~1.25 eV. The technique leads to significant improvement in the crystallinity of the films compared to the samples deposited on convention crystalline semiconductors or soda lime glass. The absorption coefficient, α, is of the order of 104 cm-1 with sharp cutoff in energy indicating low concentration of bandgap states. Hole mobility of ~81 cm2V-1s-1 was observed for SnS films on graphene/GaAs(100) substrates.
Keywords :
absorption coefficients; energy gap; hole mobility; molecular beam epitaxial growth; photoexcitation; semiconductor epitaxial layers; semiconductor growth; tin compounds; van der Waals forces; C-GaAs; MBE; SnS; absorption coefficient; band gap states; convention crystalline semiconductors; crystallinity; epitaxial growth quality; graphene-GaAs(100) substrates; hole mobility; indirect band gap; layered substrates; mica; molecular beam epitaxy; photoabsorption measurements; soda lime glass; thin films; van der Waals epitaxy; Buffer layers; Gallium arsenide; Graphene; Molecular beam epitaxial growth; Substrates; SnS; molecular beam epitaxy; photovoltaics; van der Waals Epitaxy;
Conference_Titel :
Electron Devices and Solid State Circuit (EDSSC), 2012 IEEE International Conference on
Conference_Location :
Bangkok
Print_ISBN :
978-1-4673-5694-7
DOI :
10.1109/EDSSC.2012.6482879
