Enhancement of photovoltaic effect in nanoscale polarization graded ferroelectrics

In this work, we propose the compositionally graded ferroelectrics (CGF) as solar energy harvesting device. Such a novel geometrically frustrated system exhibits an intrinsic built-in potential which can be used to separate the hole and electron currents. It is shown that the CGF based photovoltaic devices can achieve orders of higher efficiency than bulk/non-graded ferroelectric thin films. The dependence of the photovoltaic effect on various device parameters have also been investigated. 2011 Elsevier Ltd. All rights reserved.