An ultrasensitive molybdenum-based double-heterojunction phototransistor.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34215747.
- Also identified by DOI 10.1038/s41467-021-24397-x and PMC identifier 8253832.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Two-dimensional (2D) materials are promising for next-generation photo detection because of their exceptional properties such as a strong interaction with light, electronic and optical properties that depend on the number of layers, and the ability to form hybrid structures. However, the intrinsic detection ability of 2D material-based photodetectors is low due to their atomic thickness. Photogating is widely used to improve the responsivity of devices, which usually generates large noise current, resulting in limited detectivity. Here, we report a molybdenum-based phototransistor with MoS<sub>2</sub> channel and α-MoO<sub>3-x</sub> contact electrodes. The device works in a photo-induced barrier-lowering (PIBL) mechanism and its double heterojunctions between the channel and the electrodes can provide positive feedback to each other. As a result, a detectivity of 9.8 × 10<sup>16</sup> cm Hz<sup>1/2</sup> W<sup>-1</sup> has been achieved. The proposed double heterojunction PIBL mechanism adds to the techniques available for the fabrication of 2D material-based phototransistors with an ultrahigh photosensitivity.