High‐Performance Near‐Infrared Photodetector Based on Ultrathin Bi2O2Se Nanosheets. (10th January 2018) - Li, Jie
Abstract: As an emerging 2D layered material, Bi2 O2 Se has shown great potential for applications in thermoelectric and electronics, due to its high carrier mobility, near‐ideal subthreshold swing, and high air‐stability. Although Bi2 O2 Se has a suitable band gap for infrared (IR) applications, its photoresponse properties have not been investigated. Here, high‐quality ultrathin Bi2 O2 Se sheets are synthesized via a low‐pressure chemical vapor deposition method. The thickness of 90% Bi2 O2 Se sheets is below 10 nm and lateral sizes mainly distribute in the range of 7–11 µm. In addition, it is found that triangular sheets largely lack "O" content, even only 0.2 for Bi2 O0.2 Se. The near‐IR photodetection performance of Bi2 O2 Se nanosheets is systematically studied by variable temperature measurements. The response time, responsivity, and detectivity can approach up to 2.8 ms, 6.5 A W −1, and 8.3 × 10 11 Jones, respectively. Additionally, the critical performance parameters, including responsivity, rising time, and decay time, remain at almost the same level when the temperature is changed from 80 to 300 K. These phenomena are likely due to the fact that as‐grown ultrathin Bi2 O2 Se sheets have no surface trap states and shallow defect energy levels. The findings indicate ultrathin Bi2 O2 Se sheets have great potentials for future applications in ultrafast, flexible near‐IR optoelectronic devices. Abstract : The near‐infrared photodetection of as‐grown Bi2 O2 Se nanosheets is systematically studied. The critical performance parameters, including responsivity as well as rising and decay times, remain at almost the same level with the temperature is changed from 80 to 300 K. These phenomena are likely due to the fact that ultrathin Bi2 O2 Se sheets have no surface trap states and shallow defect energy levels.