Improved performance and stability of photoelectrochemical water-splitting Si system using a bifacial design to decouple light harvesting and electrocatalysis
Tsai, Meng Lin
KAUST DepartmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Electrical Engineering Program
KAUST Solar Center (KSC)
Nano Energy Lab
PRIMALIGHT Research Group
Physical Science and Engineering (PSE) Division
Online Publication Date2020-01-13
Print Publication Date2020-04
Embargo End Date2022-01-13
Permanent link to this recordhttp://hdl.handle.net/10754/661493
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AbstractPhotoelectrochemical (PEC) splitting of water into hydrogen and oxygen is a promising way for the production of clean, and storable form of fuel but the PEC efficiency has remained low. Herein, we demonstrate enhanced light harvesting, charge carrier separation/transfer, and catalyst management with bifacial design for the Si-based photocathodes to achieve best-in-class hydrogen generation with excellent electrochemical stability. Decoupling the light harvesting side from the electrocatalytic surface nullifies parasitic light absorption and enables Si photocathodes that exhibit a photocurrent density of 39.01 mA/cm2 and stability over 370 h in 1 M H2SO4(aq) electrolyte due to fully covered a 15 nm Pt without any intentional protective layer. Furthermore, the bifacial Si photocathode system with semi-transparent Pt layer of 5 nm developed herein are capable of collecting sunlight not only on the light harvesting side but also on the back side of the device, resulting in a photocurrent density of 61.20 mA/cm2 under bifacial two-sun illumination, which yields 56.88% of excess hydrogen when compared to the monofacial PEC system. Combining the bifacial design with surface texturing and antireflection coating enables excellent omnidirectional light harvesting capability with a record hydrogen (photocurrent) generation, which provides a promising way to realize practical PEC water splitting applications.
CitationFu, H.-C., Varadhan, P., Tsai, M.-L., Li, W., Ding, Q., Lin, C.-H., … He, J.-H. (2020). Improved performance and stability of photoelectrochemical water-splitting Si system using a bifacial design to decouple light harvesting and electrocatalysis. Nano Energy, 70, 104478. doi:10.1016/j.nanoen.2020.104478
SponsorsJ.H.H. greatly acknowledges the baseline funding from King Abdullah University of Science and Technology (KAUST), KAUST Sensor Initiatives, KAUST Solar Center, and KAUST Catalysis Center. S.J. thanks the support from the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under award DE-FG02-09ER46664.