Ag2S-AgInS2: p-n junction heteronanostructures with quasi type-II band alignment.

We report here the fabrication of a p-n junction diode in a single nanostructure by synthesizing a heterostructure involving n-type AgInS2 and p-type Ag2S. The quasi type-II band alignment between these ternary-binary semiconductors in the p-n junction heterostructures also slows down the carrier recombination rate and the heterostructures show rectification behavior. Hence, they can be used as an active material for fabrication of bulk heterojunction photovoltaic devices without any additional semiconductor material or dye required for charge separation or formation of a p-n junction.

Doped semiconductor nanocrystal based fluorescent cellular imaging probes.

Doped semiconductor nanocrystals such as Mn doped ZnS, Mn doped ZnSe and Cu doped InZnS, are considered as new classes of fluorescent biological probes with low toxicity. Although the synthesis in high quality of such nanomaterials is now well established, transforming them into functional fluorescent probes remains a challenge. Here we report a fluorescent cellular imaging probe made of high quality doped semiconductor nanocrystals.

Influence of doping on semiconductor nanocrystals mediated charge transfer and photocatalytic organic reaction.

Doped and undoped ZnS semiconductor nanocrystals having different recombination pathways are explored to study the charge transfer reaction between the nanocrystals and the 4-nitrophenol/sodium borohydride redox couple.