The 24-year-old has signed a deal until the summer of 2026. There is an option for an additional year.
Brentford head coach Thomas Frank said: “Rico has seamlessly made the step up to the Premier League. Defensively he is fantastic, and you can see the way he defends one on one against some great attackers.
"He is also contributing up the field with the way he can arrive in the penalty area, as we have seen this season. There are bits to work on, but it is great that he will continue that development with us."
