  Motivated by the recent experimental progress in the $ \Lambda_c $ decay that
contains a neutron in the final state, we analyze the semileptonic decay $
\Lambda_c \rightarrow n \ell \nu_\ell $ in the framework of QCD sum rules. The
transition form factors are analytically computed using three-point correlation
functions and the Cutkosky cutting rules, which can be extrapolated into the
physical region by employing the $ z $-series parametrization. The branching
fractions of $ \Lambda_c \rightarrow n e^+ \nu_e $ and $ \Lambda_c \rightarrow
n \mu^+ \nu_{\mu} $ are estimated to be $ (0.281\pm 0.056)\%$ and $ (0.275\pm
0.055)\% $, respectively. Furthermore, we calculate as well the relevant decay
asymmetry observables sensitive to new physics beyond the standard model. The
numerical results of semileptonic decays $ \Lambda_c \rightarrow \Lambda \ell
\nu_\ell $ are also given and confronted to the latest experimental data.
