Surface plasmon assisted hot electron collection in wafer-scale metallic-semiconductor photonic crystals.
Plasmon assisted photoelectric hot electron collection in a metal-semiconductor junction can allow for sub-bandgap optical to electrical energy conversion. Here we report hot electron collection by wafer-scale Au/TiO2metallic-semiconductor photonic crystals (MSPhC), with a broadband photoresponse below the bandgap of TiO2. Multiple absorption modes supported by the 2D nano-cavity structure of the MSPhC extend the photon-metal interaction time and fulfill a broadband light absorption. The surface plasmon absorption mode provides access to enhanced electric field oscillation and hot electron generation at the interface between Au and TiO2. A broadband sub-bandgap photoresponse centered at 590 nm was achieved due to surface plasmon absorption. Gold nanorods were deposited on the surface of MSPhC to study localized surface plasmon (LSP) mode absorption and subsequent injection to the TiO2catalyst at different wavelengths. Applications of these results could lead to low-cost and robust photo-electrochemical applications such as more efficient solar water splitting.
Jeffrey B
JB
Chou
Xin-Hao
XH
Li
Yu
Y
Wang
David P
DP
Fenning
Asmaa
A
Elfaer
Jaime
J
Viegas
Mustapha
M
Jouiad
Yang
Y
Shao-Horn
Sang-Gook
SG
Kim