title: Tuning the band gap and polarization of BaSnO3/SrSnO3superlattices for photovoltaic applications.
abstract: Band gap and polarization are two important quantities for enhancing the performance of photovoltaic materials. Based on first-principles calculations, we demonstrate that direct band gap and hybrid improper ferroelectric polarization coexist in BaSnO3/SrSnO3superlattices. Furthermore, the band gap and polarization can be simultaneously tuned by mechanical strain and pressure. In the presence of tensile strain or negative pressure, the band gap is substantially lowered and the polarization is enhanced by about five times in comparison with that without mechanical loads. The lowered band gap is necessary for increasing the efficiency of light absorption, whereas the enhanced polarization is desirable for the separation of photo-excited carriers in the materials. The present work suggests that the strained BaSnO3/SrSnO3superlattices are promising ferroelectric semiconducting materials for photovoltaic applications.
authors.affiliation: Department of Engineering Mechanics, School of Aeronautics and Astronautics, Zhejiang University, 38 Zheda Road, Hangzhou 310007, China. jw@zju.edu.cn.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Engineering Mechanics, School of Aeronautics and Astronautics, Zhejiang University, 38 Zheda Road, Hangzhou 310007, China. jw@zju.edu.cn and Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou 310007, China and Department of Physics, RGUKT IIIT, Nuzvid Campus, Andhra Pradesh, India.
authors.forename: M P K
authors.initials: MP
authors.lastname: Sahoo
authors.affiliation: Department of Engineering Mechanics, School of Aeronautics and Astronautics, Zhejiang University, 38 Zheda Road, Hangzhou 310007, China. jw@zju.edu.cn and Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou 310007, China.
authors.forename: Jie
authors.identifier: http://orcid.org/0000-0001-7854-9376
authors.initials: J
authors.lastname: Wang