The photogalvanic effect in media lacking a center of symmetry

Single ferroelectric-domain photovoltaic switch based on lateral BiFeO3 cells

“…1,2 This effect is distinct from that of typical semiconductor p-n junction photovoltaics and excitonic heterojunction photovoltaics in that the photogenerated carriers can be separated along the inherent polar directions, ensuing the unidirectional photocurrent (I ph ) and photovoltage (V ph ), associated with the spontaneous ferroelectric polarization vector (P s ). Therein, the open-circuit voltage (V oc ) is determined by the magnitude of the remanent polarization of ferroelectrics, and it can be additively as large as a few hundreds of volts, although the short-circuit current (I sc I ph at 0 V) is low due to the insulating character of the system.…”

“…In general, the spatial extent of spontaneous polarization vectors in ferroelectric crystals is typically manifested as domains (typically spanning over a few mm in size) and domain walls (DW, 1-2 nm in width), which must intimately determine the polarization-switching characteristics in a ferroelectric continuum. [1][2][3][4][8][9][10] In this study, we demonstrate a single-domain photovoltaic switch based on a lateral BFO channel with voltage pulses, in which coherent switching is achieved on a time scale as fast as 10 ms. By employing spatially and spectrally resolved I ph imaging on a single domain, we provide direct evidence that the photovoltaic switching characteristics are determined by the internal polarization vector along the applied electrical field (E-field). In addition, in multidomain channels, we show that oxygen vacancy accumulation at the domain walls (DWs), characteristic of perovskite oxides, is intimately associated with the diffusive switching characteristics.…”

Physical aspects of ferroelectric semiconductors for photovoltaic solar energy conversion

“…28. Here, under non-equilibrium illumination, charge carriers are created with a built-in momentum (Glass et al, 1974,Belinicher, 1980,Von Baltz and Kraut, 1981,Sturman and Fridkin, 1992,Young et al, 2012,Zenkevich et al, 2014 that creates a directed photogalvanic current. The asymmetric charge generation creates so-called shift currents (labeled as shift J in Fig.…”

“…As the hybrid and organic perovskites have been most extensively reviewed in the literature they will not be further treated in the present report. Several excellent review articles have been presented in recent years on ferroelectric photovoltaics (Sheu et al, 2012,Yuan et al, 2014,Butler et al, 2015) (Akbashev et al, 2016,Paillard et al, 2016 and on the physical properties of ferroelectric materials (Naber et al, 2010,Pintilie, 2011 that updated the early treatises (Fridkin, 1979,Belinicher, 1980,Ruppel et al, 1982,Sturman and Fridkin, 1992. The present work aims at taking a new stance of analysis of the state of the art by examining the specific physical mechanisms and device properties that determine the photovoltaic response of the solar cells based on ferroelectric materials.…”

Optical properties of Sb(Se,Te)I and photovoltaic applications

“…Research into the photorefractive effect has led to the discovery of a new mechanism for charge generation in FE, the anomalous photovoltaic effect. The FE-PV effect is observed in materials with no centre of symmetry, and several mechanisms responsible for this effect have been described [3,4]. Therefore a photoferroelectric crystal could be a possible solar energy converter.…”