TY - JOUR
T1 - Electrical, Photoelectrochemical, and Photoelectron Spectroscopic Investigation of the Interfacial Transport and Energetics of Amorphous TiO2/Si Heterojunctions
AU - Hu, Shu
AU - Richter, Matthias H.
AU - Lichterman, Michael F.
AU - Beardslee, Joseph
AU - Mayer, Thomas
AU - Brunschwig, Bruce S.
AU - Lewis, Nathan S.
PY - 2016/2/18
Y1 - 2016/2/18
N2 - Solid-state electrical, photoelectrochemical, and photoelectron spectroscopic techniques have been used to characterize the behavior and electronic structure of interfaces between n-Si, n+-Si, or p+-Si surfaces and amorphous coatings of TiO2 formed using atomic-layer deposition. Photoelectrochemical measurements of n-Si/TiO2/Ni interfaces in contact with a series of one-electron, electrochemically reversible redox systems indicated that the n-Si/TiO2/Ni structure acted as a buried junction whose photovoltage was independent of the formal potential of the contacting electrolyte. Solid-state current-voltage analysis indicated that the built-in voltage of the n-Si/TiO2 heterojunction was 0.7 V, with an effective Richardson constant 1/100th of the value of typical Si/metal Schottky barriers. X-ray photoelectron spectroscopic data allowed formulation of energy band-diagrams for the n-Si/TiO2, n+-Si/TiO2, and p+-Si/TiO2 interfaces. The XPS data were consistent with the rectifying behavior observed for amorphous TiO2 interfaces with n-Si and n+-Si surfaces and with an ohmic contact at the interface between amorphous TiO2 and p+-Si.
AB - Solid-state electrical, photoelectrochemical, and photoelectron spectroscopic techniques have been used to characterize the behavior and electronic structure of interfaces between n-Si, n+-Si, or p+-Si surfaces and amorphous coatings of TiO2 formed using atomic-layer deposition. Photoelectrochemical measurements of n-Si/TiO2/Ni interfaces in contact with a series of one-electron, electrochemically reversible redox systems indicated that the n-Si/TiO2/Ni structure acted as a buried junction whose photovoltage was independent of the formal potential of the contacting electrolyte. Solid-state current-voltage analysis indicated that the built-in voltage of the n-Si/TiO2 heterojunction was 0.7 V, with an effective Richardson constant 1/100th of the value of typical Si/metal Schottky barriers. X-ray photoelectron spectroscopic data allowed formulation of energy band-diagrams for the n-Si/TiO2, n+-Si/TiO2, and p+-Si/TiO2 interfaces. The XPS data were consistent with the rectifying behavior observed for amorphous TiO2 interfaces with n-Si and n+-Si surfaces and with an ohmic contact at the interface between amorphous TiO2 and p+-Si.
UR - http://www.scopus.com/inward/record.url?scp=84959036580&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84959036580&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.5b09121
DO - 10.1021/acs.jpcc.5b09121
M3 - Article
AN - SCOPUS:84959036580
VL - 120
SP - 3117
EP - 3129
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 6
ER -