Del Pozo-Zamudio, O. and Schwarz, S. and Sich, M. and Bayer, M. and Schofield, R. and A. Chekhovich, E. and Robinson, Benjamin and Kay, Nicholas and Kolosov, Oleg and Dmitriev, A. and Lashkia, George V. and Borisenko, D. and Kolesnikov, N. and Tartakovskii, A. I. (2015) Photoluminescence of two-dimensional GaTe and GaSe films. 2D Materials, 2 (3): 035010. ISSN 2053-1583
2015_Photoluminescence_of_two_dimensional_GaTe_and_GaSe_films.pdf - Published Version
Available under License Creative Commons Attribution.
Download (2MB)
Abstract
Gallium chalcogenides are promising building blocks for novel van der Waals heterostructures. We report on the low-temperature micro-photoluminescence (PL) of GaTe and GaSe films with thicknesses ranging from 200 nm to a single unit cell. In both materials, PL shows a dramatic decrease by 10^4–10^5 when film thickness is reduced from 200 to 10 nm. Based on evidence from continuous-wave (cw) and time-resolved PL, we propose a model explaining the PL decrease as a result of non-radiative carrier escape via surface states. Our results emphasize the need for special passivation of two-dimensional films for optoelectronic applications.