as the title, I want to know the complex representations of the B(2，Fp's algebraic closure) (invertible upper triangle matrix groups over Fp's algebraic closure)...

I know some irreducible representations of this group which can be constructed through Mackey method(B=AH...balabala). But I do not know are these irreducible representations are the whole irreducible representations. The original Mackey's method was established for finite groups， I don't know can it be extended to infinite groups.