Unassisted photoelectrochemical water splitting exceeding 7% solar-to-hydrogen conversion efficiency using photon recycling.
Various tandem cell configurations have been reported for highly efficient and spontaneous hydrogen production from photoelectrochemical solar water splitting. However, there is a contradiction between two main requirements of a front photoelectrode in a tandem cell configuration, namely, high transparency and high photocurrent density. Here we demonstrate a simple yet highly effective method to overcome this contradiction by incorporating a hybrid conductive distributed Bragg reflector on the back side of the transparent conducting substrate for the front photoelectrochemical electrode, which functions as both an optical filter and a conductive counter-electrode of the rear dye-sensitized solar cell. The hybrid conductive distributed Bragg reflectors were designed to be transparent to the long-wavelength part of the incident solar spectrum (λ>500 nm) for the rear solar cell, while reflecting the short-wavelength photons (λ<500 nm) which can then be absorbed by the front photoelectrochemical electrode for enhanced photocurrent generation.
Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.|Department of Mechanical Engineering, Stanford University, Stanford, California 94305, USA.
Xinjian
X
Shi
Department of Materials Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang 790-784, Korea.
Hokyeong
H
Jeong
Department of Materials Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang 790-784, Korea.
Seung Jae
SJ
Oh
Department of Chemical Engineering, School of Chemical Engineering and SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Chunchun-dong, Suwon 440-746, Korea.
Ming
M
Ma
Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Kan
K
Zhang
Department of Chemical Engineering, School of Chemical Engineering and SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Chunchun-dong, Suwon 440-746, Korea.
Jeong
J
Kwon
Global GET-Future Lab, Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700, Korea.
In Taek
IT
Choi
Department of Materials Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang 790-784, Korea.
Il Yong
0000-0002-8684-4495
IY
Choi
Global GET-Future Lab, Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700, Korea.
Hwan Kyu
HK
Kim
Department of Materials Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang 790-784, Korea.
Jong Kyu
JK
Kim
Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Jong Hyeok
JH
Park