Materials Science and Device Architecture for Novel Ferroelectric/Nanostructure-based High-Efficiency Photovoltaic Device
O. Auciello, L.E. Ocola, S. Hong, A. Petford-Long, S. Nakhamanson
Argonne National Laboratory, US
Keywords: Ferroelectric, films, photovoltaic, capacitor
Abstract:We are investigating a novel concept to produce high-efficiency photovoltaic devices based on ferroelectric thin films integrated with solar wavelength spectrum- absorbing materials on glass substrates via heterostructured transparent oxide electrodes. Prior work on ferroelectric film-based Pb(ZrxTi1-x)O3 (PZT) capacitors shows that critical interfaces exist between the glass substrate and a transparent conductive oxide (such as ITO), between the ITO and a template layer (such as LNO) and between the template layer and the ferroelectric thin film. We have found that the inserted layer of LNO provides the lattice matching needed to grow highly oriented PZT layers on high-conductivity ITO transparent electrode layers on glass. Initial studies recently performed at Argonne have shown several orders of magnitude increase in output current from ITO/LaNiO3(LNO)/Pb(ZrxTi1-x)O3(PZT)/LNO/ITO capacitors when exposed to sun light over the capacitors. Preliminary measurements of photocurrents in transparent PZT capacitors showed enhanced photo-induced current during current-voltage measurements. Current-voltage (I-V) curves were taken with and without illumination. An unperturbed transparent capacitor shows an increase in photocurrent from 3.7×10-11 A to 3.9×10-5 A at ~7V.