Open AccessPhotonic crystal based photoelectrochemical cell for solar fuels
Author(s) -
Zhang Xiwen,
John Sajeev
Publication year - 2021
Publication title -
nano select
Language(s) - English
Resource type - Journals
ISSN - 2688-4011
DOI - 10.1002/nano.202000143
Subject(s) - photocurrent , materials science , photonic crystal , dielectric , optoelectronics , penetration depth , charge carrier , visible spectrum , absorption (acoustics) , energy conversion efficiency , diffusion , optics , physics , composite material , thermodynamics
The solar fuel production efficiency of photoelectrochemical cells based on TiO 2 is primarily limited by the low optical absorption coefficient and concomitant long penetration depth of visible light compared with the minority charge carrier diffusion length. A TiO 2 photoelectrode consisting of a slanted conical‐pore photonic crystal immersed in water and integrated on a reflective back‐contact is proposed to reduce the light penetration depth by more than 10 times and branch the electron and hole transports into dimensions matching their diffusion lengths. This brings the photoelectrolytic process into the high‐efficiency operating regime. The maximum achievable photocurrent density for a lightly doped TiO 2 with the imaginary part of the dielectric constant 0.01 in the visible range reaches 7.65 mA cm ‐2 .