Open AccessStrongly enhanced and tunable photovoltaic effect in ferroelectric-paraelectric superlattices
Author(s) -
Yeseul Yun,
Lutz Mühlenbein,
David S. Knoche,
Andriy Lotnyk,
Akash Bhatnagar
Publication year - 2021
Publication title -
science advances
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.928
H-Index - 146
ISSN - 2375-2548
DOI - 10.1126/sciadv.abe4206
Subject(s) - superlattice , ferroelectricity , photovoltaic system , dielectric , materials science , optoelectronics , nanotechnology , biology , ecology
Ever since the first observation of a photovoltaic effect in ferroelectric BaTiO 3 , studies have been devoted to analyze this effect, but only a few attempted to engineer an enhancement. In conjunction, the steep progress in thin-film fabrication has opened up a plethora of previously unexplored avenues to tune and enhance material properties via growth in the form of superlattices. In this work, we present a strategy wherein sandwiching a ferroelectric BaTiO 3 in between paraelectric SrTiO 3 and CaTiO 3 in a superlattice form results in a strong and tunable enhancement in photocurrent. Comparison with BaTiO 3 of similar thickness shows the photocurrent in the superlattice is 10 3 times higher, despite a nearly two-thirds reduction in the volume of BaTiO 3 The enhancement can be tuned by the periodicity of the superlattice, and persists under 1.5 AM irradiation. Systematic investigations highlight the critical role of large dielectric permittivity and lowered bandgap.