  Gallium chalcogenides are promising building blocks for novel van der Waals
heterostructures. We report low-temperature micro-photoluminescence (PL) of
GaTe and GaSe films with thickness ranging from from 200 nm to a single unit
cell. In both materials, PL shows dramatic decrease by 10$^4$-10$^5$ when film
thickness is reduced from 200 to 10 nm. Based on evidence from cw and
time-resolved PL, we propose a model explaining the PL decrease as a result of
non-radiative carrier escape via surface states.
