High-Performance WSe<sub>2</sub> Phototransistors with 2D/2D Ohmic Contacts.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 29614223.
- Also identified by DOI 10.1021/acs.nanolett.7b04205.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
We report high-performance WSe<sub>2</sub> phototransistors with two-dimensional (2D) contacts formed between degenerately p-doped WSe<sub>2</sub> and undoped WSe<sub>2</sub> channel. A photoresponsivity of ∼600 mA/W with a high external quantum efficiency up to 100% and a fast response time (both rise and decay times) shorter than 8 μs have been achieved concurrently. More importantly, our WSe<sub>2</sub> phototransistor exhibits a high specific detectivity (∼10<sup>13</sup> Jones) in vacuum, comparable or higher than commercial Si- and InGaAs-based photodetectors. Further studies have shown that the high photoresponsivity and short response time of our WSe<sub>2</sub> phototransistor are mainly attributed to the lack of Schottky-barriers between degenerately p-doped WSe<sub>2</sub> source/drain contacts and undoped WSe<sub>2</sub> channel, which can reduce the RC time constant and carrier transit time of a photodetector. Our experimental results provide an accessible strategy to achieve high-performance WSe<sub>2</sub> phototransistor architectures by improving their electrical transport and photocurrent generation simultaneously, opening up new avenues for engineering future 2D optoelectronic devices.