Creation
Jeff Wu was created by Paul Tobin as a character of “Falling Skies”. He only appeared in the comic-series and not the TV series.
Falling Skies (comics)
Jeff Wu was a friend of Anthony and Click. The three of them saw the posters of the 2nd Mass and that’s where the “freedom trail got them”. They went to the old house of a guy named Paul Rever, where Karen Nadler was waiting for new survivors of the Earth Invasion. Then she guided Jeff, Anthony and Click the rest of the way but Jeff was afraid that the Skitters could the english words on the posters.
An hour later, Jeff was with his friends, Dai, Tom Mason and a woman named Grenice out on a mission to finde Alex Vlensa, an old friend and colleague of Tom. They found the building in which Vlensa used to live but it was nearly destroyed.
The fate of Jeff
It isn’t revealed what happend to Jeff. He wasn’t seen or even mentioned since Falling Skies #2. It is both possible: that he is still alive or that he’s dead.