Fast Yet Quantum‐Efficient Few‐Layer Vertical MoS2 Photodetectors. (23rd May 2019)

• Record Type: Journal Article
• Authors: Maeso, David; Castellanos‐Gomez, Andres; Agraït, Nicolas; Rubio‐Bollinger, Gabino
• Is Part Of: Advanced Electronic Materials. Volume 5:Number 7(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-05-23
• Subjects: metal‐semiconductor‐metal architecture -- molybdenum disulfide (MoS2) -- photodetectors -- Schottky interfaces -- vertical device architecture; Materials -- Electric properties -- Periodicals; Materials science -- Periodicals; Magnetic materials -- Periodicals; Electronic apparatus and appliances -- Periodicals; 537
• DOI: 10.1002/aelm.201900141
• Languages: English
• ISSNs: 2199-160X

Abstract

Abstract: Semiconducting 2D materials, such as molybdenum disulfide (MoS2 ) and other members of the transition‐metal dichalcogenide family, have emerged as promising materials for applications in high‐performance nanoelectronics that exhibit excellent electrical and optical properties. Highly efficient photocurrent (PC) generation is reported in vertical few‐layer MoS2 devices contacted with semitransparent metallic electrodes. The light absorption of the device can be improved by fabricating vertical photodevices using few‐layer flakes, achieving a photoresponse of up to 0.11 A W −1 and an external quantum efficiency (EQE) of up to 30%. Because of the vertical design, the distance between electrodes can be kept in the range of a few nanometers, thus substantially reducing the collection time of photogenerated carriers and increasing the efficiency of the devices. The wavelength‐dependent PC, photoresponsivity, and EQE are measured over a photon energy range from 1.24 to 2.58 eV. Compared to previous in‐plane and vertical devices, these vertical few‐layer MoS2 photodevices exhibit very short response time, ≈60 ns, and a cutoff frequency of 5.5 MHz, while maintaining high photoresponsivity. Abstract : Vertical few‐layer molybdenum disulfide photodevices with semitransparent metallic electrodes are fabricated. Their vertical configuration means that the electrode separation is kept in the range of a few nanometers, which reduces their collection time, increases their efficiency, and endows them with a MHz‐range response time.