The Germans were beaten 2-1 at home in the second leg of their last-16 tie, but secured their spot in the last eight 5-4 on aggregate.
The captain told reporters: "It was not our best match, but we have reached the quarter-finals and can leave with a huge smile on our face.
"We've had a lot of injuries. We never complained. Despite this, we deserve to be among the best eight teams in Europe."
The draw for the quarter-finals takes place on Friday.