optical bandgap energy measured by Tauc plot for GeGaSbS thin film was 1.712eV and for powder sample was 3.88eV. ?
Shouldn't they be the same? why so much difference?
- ElizabethLv 71 month agoFavorite Answer
A thin film is, you'd hope, a well-ordered structure. A powder grain is basically small crystallites mashed together in random orientations
You have different dislocations and defects, changes in electrostatic fields through the structures and hence different surface configurations, and completely different strain conditions.
The 'quality' of the two structures is totally different.