Limitations of the Tauc Plot Method Abstract The Tauc plot is a method originally developed to derive the optical gap of amorphous semiconductors such as amorphous germanium or silicon. By measuring the absorption coefficient α ( hν ) and plotting versus photon energy hν , a value for the optical gap ( Tauc gap ) is determined. In this way non‐direct optical transitions between approximately parabolic bands can be examined. In the last decades, a modification of this method for (poly‐) crystall...