The paper presents activities aimed at increasing physics teachers' self-confidence in the area of semiconductors, namely their practical applications. These activities have been used since 2008 at seminars of the informal Heureka project.
At the seminar, participants also actively build some simple tools that they can later use in their classes. Our experience shows that this hands-on, minds-on approach is appreciated by teachers.
Both formal and informal feedback is shortly discussed in the paper as well as (rather encouraging) results of a small survey among former participants trying to find possible long-term impact of the seminar.