Duken played his first major role on a movie screen in 1999, alongside Franka Potente and Heiner Lauterbach in Friedemann Fromm's Paradise Mall [de] (Schlaraffenland).

Duken was a member of the cast in the core produced by ZDF since 2002 police drama series Night Shift [de] by Lars Becker as a young Commissioner Teddy Schrader.

In the autumn of 2006 he was in Tolstoy's War and Peace by Robert Dornhelm in Russia and Lithuania, in which he played the role of Anatol Kuragin.

In 2003, together with Duken including Bernd Katzmarczyk and Norbert Kneissl worked with the production company Grand Hôtel Pictures.

In 2008 Duken played the role of SS Captain Siegfried Fehmer, who was head of the Gestapo in 1945 in Oslo, in the film Max Manus on the Norwegian resistance fighters.

The role of the smart ladies' man Fehmer, who could quickly change to a brutal torturer, was a good preparation for his performance in Quentin Tarantino's Inglourious Basterds (2009).