In my TMDC bulk crystal samples I am getting photoresponse in opposite direction i.e. dark current is more than illuminated current. Such type of effect is possible due to either photo-voltaic effect or photo-bolometric effect. According to references I have studied everywhere it is given that bolometric effect is observed at some biasing voltage. But just to understand and clear my doubt I want to know if bolometric effect is observable at zero biasing voltage or not. Please provide any relevant reference if possible.
Thanking you in anticipation.