title: Enhancement of the anisotropic photocurrent in ferroelectric oxides by strain gradients.
abstract: The phase separation of multiple competing structural/ferroelectric phases has attracted particular attention owing to its excellent electromechanical properties. Little is known, however, about the strain-gradient-induced electronic phenomena at the interface of competing structural phases. Here, we investigate the polymorphic phase interface of bismuth ferrites using spatially resolved photocurrent measurements, present the observation of a large enhancement of the anisotropic interfacial photocurrent by two orders of magnitude, and discuss the possible mechanism on the basis of the flexoelectric effect. Nanoscale characterizations of the photosensitive area through position-sensitive angle-resolved piezoresponse force microscopy and electron holography techniques, in conjunction with phase field simulation, reveal that regularly ordered dipole-charged domain walls emerge. These findings offer practical implications for complex oxide optoelectronics.
authors: Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
authors: Kanghyun
authors: K
authors: Chu
authors: Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
authors: Byung-Kweon
authors: BK
authors: Jang
authors: Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk 790-784, Korea.|Center for Artificial Low-Dimensional Electronic Systems, Institute for Basic Science (IBS), POSTECH, Pohang, Gyeongbuk 790-784, Republic of Korea.
authors: Ji Ho
authors: JH
authors: Sung
authors: Department of Materials Science and Engineering, POSTECH, Pohang, Gyeongbuk 790-784, Republic of Korea.
authors: Yoon Ah
authors: YA
authors: Shin
authors: Graduate School of Nanoscience and Technology, KAIST, Daejeon 305-701, Republic of Korea.
authors: Eui-Sup
authors: ES
authors: Lee
authors: Department of Materials Science and Engineering, POSTECH, Pohang, Gyeongbuk 790-784, Republic of Korea.
authors: Kyung
authors: K
authors: Song
authors: Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
authors: Jin Hong
authors: JH
authors: Lee
authors: Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
authors: Chang-Su
authors: CS
authors: Woo
authors: Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
authors: Seung Jin
authors: SJ
authors: Kim
authors: Department of Materials Modeling and Characterization, Korea Institute of Materials Science, Changwon 642-831, Republic of Korea.
authors: Si-Young
authors: http://orcid.org/0000-0003-1648-142X
authors: SY
authors: Choi
authors: Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk 790-784, Republic of Korea.
authors: Tae Yeong
authors: TY
authors: Koo
authors: Graduate School of Nanoscience and Technology, KAIST, Daejeon 305-701, Republic of Korea.
authors: Yong-Hyun
authors: http://orcid.org/0000-0003-4255-2068
authors: YH
authors: Kim
authors: Department of Materials Science and Engineering, POSTECH, Pohang, Gyeongbuk 790-784, Republic of Korea.
authors: Sang-Ho
authors: SH
authors: Oh
authors: Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk 790-784, Korea.|Center for Artificial Low-Dimensional Electronic Systems, Institute for Basic Science (IBS), POSTECH, Pohang, Gyeongbuk 790-784, Republic of Korea.|Department of Materials Science and Engineering, POSTECH, Pohang, Gyeongbuk 790-784, Republic of Korea.
authors: Moon-Ho
authors: MH
authors: Jo
authors: Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.|KAIST Institute for the NanoCentury, Daejeon 305-701, Republic of Korea.
authors: Chan-Ho
authors: CH
authors: Yang