Ultrasensitive Phototransistors Based on Few‐Layered HfS2

• DOI: 10.1002/adma.201503864
• Publication Date: 2015-10-26T07:05:49Z
• Authors: Kai Xu; Zhenxing Wang; Feng Wang; Yun Huang; Fengmei Wang; Lei Yin; Chao Jiang; Jun He
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

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.