title: Conducting Interface in Oxide Homojunction: Understanding of Superior Properties in Black TiO2.
abstract: Black TiO2 nanoparticles with a crystalline core and amorphous-shell structure exhibit superior optoelectronic properties in comparison with pristine TiO2. The fundamental mechanisms underlying these enhancements, however, remain unclear, largely due to the inherent complexities and limitations of powder materials. Here, we fabricate TiO2 homojunction films consisting of an oxygen-deficient amorphous layer on top of a highly crystalline layer, to simulate the structural/functional configuration of black TiO2 nanoparticles. Metallic conduction is achieved at the crystalline-amorphous homointerface via electronic interface reconstruction, which we show to be the main reason for the enhanced electron transport of black TiO2. This work not only achieves an unprecedented understanding of black TiO2 but also provides a new perspective for investigating carrier generation and transport behavior at oxide interfaces, which are of tremendous fundamental and technological interest.
authors.affiliation: Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.|Earth and Environmental Sciences Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Xujie
authors.initials: X
authors.lastname: Lü
authors.affiliation: Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Aiping
authors.initials: A
authors.lastname: Chen
authors.affiliation: Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Yongkang
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Sandia National Laboratories , Albuquerque, New Mexico 87185, United States.
authors.forename: Ping
authors.initials: P
authors.lastname: Lu
authors.affiliation: Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Yaomin
authors.initials: Y
authors.lastname: Dai
authors.affiliation: Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Erik
authors.initials: E
authors.lastname: Enriquez
authors.affiliation: Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Paul
authors.initials: P
authors.lastname: Dowden
authors.affiliation: Earth and Environmental Sciences Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Hongwu
authors.initials: H
authors.lastname: Xu
authors.affiliation: Sandia National Laboratories , Albuquerque, New Mexico 87185, United States.
authors.forename: Paul G
authors.initials: PG
authors.lastname: Kotula
authors.affiliation: Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Abul K
authors.initials: AK
authors.lastname: Azad
authors.affiliation: Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Yarotski
authors.affiliation: Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Rohit P
authors.initials: RP
authors.lastname: Prasankumar
authors.affiliation: Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Antoinette J
authors.initials: AJ
authors.lastname: Taylor
authors.affiliation: Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Joe D
authors.initials: JD
authors.lastname: Thompson
authors.affiliation: Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Quanxi
authors.initials: Q
authors.lastname: Jia
keywords: Black TiO2; enhanced electron transport; interfacial engineering; metallic conduction; oxide interfaces; thin films