  The challenging task of scaling-down the size of the power saving electronic
devices can be accomplished by exploiting the spin degree of freedom of the
conduction electrons in van der Waals (vdW) spintronic architectures built with
2D materials. One of the key components of such a device is a near-room
temperature 2D ferromagnet with good metallicity that can generate a highly
spin-polarized electronic transport current. However, most of the known 2D
ferromagnets have either a very low temperature ordering, poor conductivity, or
low spin polarization. In this context, the Fe$_n$GeTe$_2$ (with $n\geq3$)
family of ferromagnets stand out due to their near-room temperature
ferromagnetism and good metallicity. We have performed spin-resolved Andreev
reflection spectroscopy on Fe$_4$GeTe$_2$ ($T_{Curie} \sim$ 273 K) and
demonstrated that the ferromagnet is capable of generating a very high
transport spin polarization, exceeding 50$\%$. This makes Fe$_4$GeTe$_2$ a
strong candidate for application in all-vdW power-saving spintronic devices.
