title: Ge-mediated modification in Ta3N5 photoelectrodes with enhanced charge transport for solar water splitting.
abstract: Ta3 N5 is a promising photoanode candidate for photoelectrochemical water splitting, with a band gap of about 2.1 eV and a theoretical solar-to-hydrogen efficiency as high as 15.9 % under AM 1.5 G 100 mW cm(-2) irradiation. However, the presently achieved highest photocurrent (ca. 7.5 mA cm(-2) ) on Ta3 N5 photoelectrodes under AM 1.5 G 100 mW cm(-2) is far from the theoretical maximum (ca. 12.9 mA cm(-2) ), which is possibly due to serious bulk recombination (poor bulk charge transport and charge separation) in Ta3 N5 photoelectrodes. In this study, we show that volatilization of intentionally added Ge (5 %) during the synthesis of Ta3 N5 promotes the electron transport and thereby improves the charge-separation efficiency in bulk Ta3 N5 photoanode, which affords a 320 % increase of the highest photocurrent comparing with that of pure Ta3 N5 photoanode under AM 1.5 G 100 mW cm(-2) simulated sunlight.
authors.affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Ecomaterials and Renewable Energy Research Center, Nanjing University, 22 Hankou Road, Nanjing 210093 (P.R. China).
authors.forename: Jianyong
authors.initials: J
authors.lastname: Feng
authors.forename: Dapeng
authors.initials: D
authors.lastname: Cao
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Wang
authors.forename: Wenjun
authors.initials: W
authors.lastname: Luo
authors.forename: Jiajia
authors.initials: J
authors.lastname: Wang
authors.forename: Zhaosheng
authors.initials: Z
authors.lastname: Li
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zou
keywords: charge transfer; electron transport; energy conversion; photochemistry; tantalum nitride