Studies of optical properties and SHI irradiation on PbS sensitized nanoporous TiO2 network

Abstract

Titania is a well-known oxide system intended for use in a wide variety of applications. Nanocrystalline titania can be deposited on substrates in the form of thick and thin films. This paper studies the PbS nanoparticle growth in nanoporous network of TiO2 along with its promising properties after incorporation of PbS nanoparticles. PbS nanoparticles are ultra small particles, with dimension 1-100 nm, exhibit discrete electronic states along with other interesting properties. Due to extremely large surface-to-volume ratio (>1), nanoparticle possess inherent defect sites in the form of intermediate states/surface states located in the forbidden gap. When one nanoparticle system is clubbed with another nanoparticle system then it is most likely to exhibit typical phenomena where electron can tunnel from one particle to the other. Formation of PbS quantum dots was analyzed by SEM, AFM, XRD, TEM and PL. Controlled heating effect is studied if there is any change in structure of this system. Interfacial charge transfer between the surface states of PbS and TiO2 was studied through comparative photoluminescence of this system. Results obtained from these studies infer that the coupled system of PbS/TiO2 can be made useful for single electron devices, quantum point contacts and other optoelectronics applications.