Acceptor-compensated charge transport and surface chemical reactions in Au-implanted SnO₂ nanowires.
A new deep acceptor state is identified by density functional theory calculations, and physically activated by an Au ion implantation technique to overcome the high energy barriers. And an acceptor-compensated charge transport mechanism that controls the chemical sensing performance of Au-implanted SnO2 nanowires is established. Subsequently, an equation of electrical resistance is set up as a function of the thermal vibrations, structural defects (Au implantation), surface chemistry (1 ppm NO2), and solute concentration. We show that the electrical resistivity is affected predominantly not by the thermal vibrations, structural defects, or solid solution, but the surface chemistry, which is the source of the improved chemical sensing. The response and recovery time of chemical sensing is respectively interpreted from the transport behaviors of major and minor semiconductor carriers. This acceptor-compensated charge transport mechanism provides novel insights not only for sensor development but also for research in charge and chemical dynamics of nano-semiconductors.
Department of Materials Science and Engineering, Inha University, Incheon 402-751, Republic of Korea.
Akash
A
Katoch
Department of Materials Science and Engineering, Inha University, Incheon 402-751, Republic of Korea.
Gun-Joo
GJ
Sun
Department of Materials Science and Engineering, Inha University, Incheon 402-751, Republic of Korea.
Sun-Woo
SW
Choi
National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan.
Shunichi
S
Hishita
Entropic Interface Group, Singapore University of Technology & Design, Singapore 138682, Singapore.
Vadym V
VV
Kulish
Entropic Interface Group, Singapore University of Technology & Design, Singapore 138682, Singapore.
Ping
P
Wu
Department of Materials Science and Engineering, Inha University, Incheon 402-751, Republic of Korea.
Sang Sub
SS
Kim