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Band Edge Engineering of Oxide Photoanodes for Photoelectrochemical Water Splitting: Integration of Subsurface Dipoles with Atomic‐Scale Control |
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| Authors: | Yasuyuki Hikita Kazunori Nishio Linsey C Seitz Pongkarn Chakthranont Takashi Tachikawa Thomas F Jaramillo Harold Y Hwang |
| Institution: | 1. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, USA;2. Geballe Laboratory for Advanced Materials, Department of Applied Physics, Stanford University, Stanford University, Stanford, CA, USA;3. Department of Chemical Engineering, Stanford University, Shriram Center, Stanford, CA, USA;4. SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, Menlo Park, CA, USA |
| Abstract: | One of the crucial parameters dictating the efficiency of photoelectrochemical water‐splitting is the semiconductor band edge alignment with respect to hydrogen and oxygen redox potentials. Despite the importance of metal oxides in their use as photoelectrodes, studies to control the band edge alignment in aqueous solution have been limited predominantly to compound semiconductors with modulation ranges limited to a few hundred mV. The ability to modulate the flat band potential of oxide photoanodes by as much as 1.3 V, using the insertion of subsurface electrostatic dipoles near a Nb‐doped SrTiO3/aqueous electrolyte interface is reported. The tunable range achieved far exceeds previous reports in any semiconductor/aqueous electrolyte system and suggests a general design strategy for highly efficient oxide photoelectrodes. |
| Keywords: | interface dipoles oxide/electrolyte interfaces photoelectrochemical cells solar water splitting photoanodes |