Ultrasensitive Phototransistors Based on Few-Layered HfS2.
An ultrathin HfS2 -based ultrasensitive phototransistor is systematically studied. Au-contacted HfS2 phototransistors with ideal thickness ranging from 7 to 12 nm exhibit a high on/off ratio of ca. 10(7) , ultrahigh photoresponsivity over 890 A W(-1) , and photogain over 2300. Moreover, the response time is strongly dependent on the back-gate voltage and shows a reverse trend for Au and Cr metals.
National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Kai
K
Xu
National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Zhenxing
Z
Wang
National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Feng
F
Wang
National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Yun
Y
Huang
National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Fengmei
F
Wang
National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Lei
L
Yin
National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Chao
C
Jiang
National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Jun
J
He
HfS2; flake thickness; metal contacts; phototransistors; responsivity