Current Research
My current research work focuses on the effect of ligh-induced degradation on hydrogenated amorphous/nanocrystalline silicon thin films for photovoltaic applications. Hydrogenated amorphous silicon (a-Si:H) is a well-accepted photovoltaic material for its easy and low-cost fabrication; however it is limited by light induced degradation (LID) which degrades the conductivity of the material after being illuminated over a prolonged time. The disordered structure of amorphous matrix has been considered as the main reason for this degradation, which leds the researchers to introduce crystalline phase in the amorphous matrix. This mixed phase amorphous – nanocrystalline silicon structure improves material quality and device performance but still is not completely free from photo induced metastability. Several studies have been done so far to explain the origin and microscopic model of LID in hydrogenated amorphous silicon; however an appropriate and well-suited model of LID in nanocrystalline silicon is yet to be established. Although the silicon-hydrogen (Si-H) bonding configuration has pointed out some important physical phenomena behind LID, the effect of grain and grain/grain-boundary interface is still not comprehended properly. I am investigating this less explored area of grain/grain-boundary contribution on nanoscale charge transport in the aforementioned material to explain metastability in a well-suited manner.