Kim, Donghoon Han, Hyeon Lee, June Ho Choi, Jin Woo Grossman, Jeffrey C. Jang, Hyun Myung Kim, Donghun 2024-01-19T22:31:51Z 2024-01-19T22:31:51Z 2021-09-03 2018-06-26 0027-8424 https://pubs.kist.re.kr/handle/201004/121240 Despite their potential to exceed the theoretical Shockley-Queisser limit, ferroelectric photovoltaics (FPVs) have performed inefficiently due to their extremely low photocurrents. Incorporating Bi2FeCrO6 (BFCO) as the light absorber in FPVs has recently led to impressively high and record photocurrents [Nechache R, et al. (2015) Nat Photonics 9:61-67], which has revived the FPV field. However, our understanding of this remarkable phenomenon is far from satisfactory. Here, we use first-principles calculations to determine that such excellent performance mainly lies in the efficient separation of electron-hole (e-h) pairs. We show that photoexcited electrons and holes in BFCO are spatially separated on the Fe and Cr sites, respectively. This separation is much more pronounced in disordered BFCO phases, which adequately explains the observed exceptional PV responses. We further establish a design strategy to discover next-generation FPV materials. By exploring 44 additional Bi-based double-perovskite oxides, we suggest five active-layer materials that offer a combination of strong e-h separations and visible-light absorptions for FPV applications. Our work indicates that charge separation is the most important issue to be addressed for FPVs to compete with conventional devices. English NATL ACAD SCIENCES LIMIT Electron-hole separation in ferroelectric oxides for efficient photovoltaic responses Article 10.1073/pnas.1721503115 1 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, v.115, no.26, pp.6566 - 6571 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 115 26 6566 6571 scie scopus 000436245000046 2-s2.0-85049029824 Multidisciplinary Sciences Science & Technology - Other Topics Article LIMIT ferroelectrics double perovskites photovoltaics e-h separation density functional theory