Solar energy conversion concept based on nanostructured materials has attracted much attention as an avenue to develop
cheaper and more efficient solar cells. Both dye molecules and quantum dots can sensitize high band gap semiconductor
by injecting carriers to the conduction band (CB) or valence band (VB) of the high band gap material, if energy band
levels are in appropriate configuration and have a suitable bond between them. However, other physical properties of
dye anchored and quantum dot embedded nanostructured semiconductor films offers the possibility of designing hybrid
systems of higher efficiency. The low efficiency of dye-sensitized solar cells is partly attributed to the poor electron
transport properties of the dye coated nanocrystalline matrix. Encapsulation of PbS quantum dots could enhance the
electronic conductivity of nanostructured ZnO films. PbS quantum dot sensitized ZnO films shows sensitizing response
to light absorption in ZnO, PbS QDs and dyes anchored to ZnO. As a result of the improvement of transport properties
by the QDs, photocurrent response of composite system due to light absorption by ZnO and dye are also enhanced.
Possibilities of adopting this concept in solar cells and multi-band photon detectors will be discussed.