[1] Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA
[2] Univ Toledo, Wright Ctr Photovolta Innovat & Commercializat, 2801 W Bancroft St, Toledo, OH 43606 USA
[3] Wuhan Univ, Key Lab Artificial Micro Nano Struct, Minist Educ, Sch Phys & Technol, Wuhan, Hubei, Peoples R China
[4] Nanchang Univ, Ordered Matter Sci Res Ctr, Nanchang, Jiangxi, Peoples R China
[5] Southeast Univ, Jiangsu Key Lab Sci & Applicat Mol Ferroelect, Nanjing, Jiangsu, Peoples R China
[6] Natl Renewable Energy Lab, Chem & Nanosci Ctr, Golden, CO USA