Driven by the energy crisis and environmental problems, scientific researchers have begun to search promising candidates for thin-film photovoltaic cells as the new generation of renewable energy production.
Photovoltaic effect observed in ferroelectric perovskite thin films such as Pb(Zr,Ti)O3 (PZT), BaTiO3 (BTO) and LiNbO3 (LNO) family, have attracted the scientist because of device miniaturization and important properties in potential applications. Recently, the emergent lower band-gap ferroelectrics oxides such as BFO (Eg~2.67eV) and BFCO (Eg~1.4-2.0eV), present an exciting opportunity to explore new ferroelectrics materials.
Epitaxial ferroelectric BFO/BFCO thin films were grown on Niobium doped SrTiO3 (Nb-STO) thin-film substrate by ablation laser. Niobium doped STO (Nb-STO) thin film is an excellent performance template material for thin-film solar cell, due to its unparalleled dielectric, ferroelectric and optical properties, its lattice constant (a=3.905Å) is similar to that of most ferroelectric perovskite oxides such as BFO, BFCO (a≈3.990Å).
My project focuses on multiferroic oxides for high photovoltaic efficient thin-film solar cell. The main objectives are: (1) Epitaxial growth of Nb doped STO single-crystal thin film (100) on silicon (100) substrate by PLD-MBE under moderate conditions such as laser power density, deposition temperatures, oxygen partial pressure, distance between target and substrate, etc.; (2) Epitaxial growth of BFCO thin film on Nb-STO thin-film (100) substrate by PLD; (3) Characteristic of nanostructures and analyze of physical properties & photovoltaic effect of thin film.