  Realizing room-temperature magnetic skyrmions in two-dimensional van der
Waals ferromagnets offers unparalleled prospects for future spintronic
applications. However, due to the intrinsic spin fluctuations that suppress
atomic long-range magnetic order and the inherent inversion crystal symmetry
that excludes the presence of the Dzyaloshinskii-Moriya interaction, achieving
room-temperature skyrmions in 2D magnets remains a formidable challenge. In
this study, we target room-temperature 2D magnet $\rm Fe_3GaTe_2$ and unveil
that the introduction of iron-deficient into this compound enables spatial
inversion symmetry breaking, thus inducing a significant Dzyaloshinskii-Moriya
interaction that brings about room-temperature N\'eel-type skyrmions with
unprecedentedly small size. To further enhance the practical applications of
this finding, we employ a homemade in-situ optical Lorentz transmission
electron microscopy to demonstrate ultrafast writing of skyrmions in $\rm
Fe_{3-x}GaTe_2$ using a single femtosecond laser pulse. Our results manifest
the $\rm Fe_{3-x}GaTe_2$ as a promising building block for realizing
skyrmion-based magneto-optical functionalities.
