High mobility ReSe2 field effect transistors : Schottky-barrier-height-dependent photoresponsivity and broadband light detection with Co decoration
(2020) In 2D Materials 7(1).- Abstract
2D transition metal dichalcogenides are promising in various electronics and optoelectronics applications and have gained popularity owing to their carrier transport and strong light-matter interactions. To fully realize their potential in field-effect transistors (FETs) and photodetectors, high mobility and high responsivity are imperative. Here, we demonstrate the highest mobility of ∼166 cm2 V-1 s-1 at 200 K for single-layer rhenium diselenide (ReSe2) FETs encapsulated between h-BN flakes at V g = 47 V. The high mobility is attributed to low-resistance contacts of scandium/gold (Sc/Au), with a low Schottky barrier height and reduced charge scattering platform of h-BN. Further, we... (More)
2D transition metal dichalcogenides are promising in various electronics and optoelectronics applications and have gained popularity owing to their carrier transport and strong light-matter interactions. To fully realize their potential in field-effect transistors (FETs) and photodetectors, high mobility and high responsivity are imperative. Here, we demonstrate the highest mobility of ∼166 cm2 V-1 s-1 at 200 K for single-layer rhenium diselenide (ReSe2) FETs encapsulated between h-BN flakes at V g = 47 V. The high mobility is attributed to low-resistance contacts of scandium/gold (Sc/Au), with a low Schottky barrier height and reduced charge scattering platform of h-BN. Further, we elucidated the Schottky-barrier-height dependent high photoresponsivity (∼3.2 × 106 A W-1) of few-layer ReSe2 (FL-ReSe2) at 532 nm-wavelength laser light on an h-BN substrate with Sc/Au contacts. Moreover, broadband light detection of undoped and Co-doped few-layer (FL) ReSe2 was performed under different laser wavelengths (400-1100 nm). After the deposition of Co nanoparticles, the photocurrent of FL-ReSe2 increased due to n-doping, as confirmed by the transfer curves of the FL-ReSe2-based undoped and co-doped FETs. Further, the work function decreased from 4.856 to 4.791 eV in FL-ReSe2, as measured by Kelvin probe force microscopy. No light signal was observed at 1100 nm for the undoped ReSe2 (1050 nm < λ cut-off < 1100 nm); however, after doping with Co nanoparticles, the cut-off wavelength exceeded to (λ cut-off > 1100 nm), due to the additional trap states generated in the energy band gap of ReSe2 after Co doping. Further, the transient response of ReSe2 and Co + ReSe2 FETs was estimated so that the rise and decay times are decreased from 1.9 s & 2.7 s to 1.1 s & 1.8 s, respectively. ReSe2 is therefore a promising semiconducting material for electrical and optoelectrical applications.
(Less)
- author
- Khan, Muhammad Farooq ; Rehman, Shania ; Akhtar, Imtisal ; Aftab, Sikandar ; Ajmal, Hafiz Muhammad Salman ; Khan, Waqar LU ; Kim, Deok Kee and Eom, Jonghwa
- organization
- publishing date
- 2020
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- high responsivity, photodetector, rhenium diselenide, Schottky barrier height, transition metal dichalcogenides
- in
- 2D Materials
- volume
- 7
- issue
- 1
- article number
- 015010
- publisher
- IOP Publishing
- external identifiers
-
- scopus:85081985281
- ISSN
- 2053-1583
- DOI
- 10.1088/2053-1583/ab4ef4
- language
- English
- LU publication?
- yes
- id
- 012b8ea1-644c-4694-a70b-7305ddbdf1f9
- date added to LUP
- 2020-04-09 08:29:06
- date last changed
- 2025-04-04 14:07:14
@article{012b8ea1-644c-4694-a70b-7305ddbdf1f9,
abstract = {{<p>2D transition metal dichalcogenides are promising in various electronics and optoelectronics applications and have gained popularity owing to their carrier transport and strong light-matter interactions. To fully realize their potential in field-effect transistors (FETs) and photodetectors, high mobility and high responsivity are imperative. Here, we demonstrate the highest mobility of ∼166 cm<sup>2</sup> V<sup>-1</sup> s<sup>-1</sup> at 200 K for single-layer rhenium diselenide (ReSe<sub>2</sub>) FETs encapsulated between h-BN flakes at V <sub>g</sub> = 47 V. The high mobility is attributed to low-resistance contacts of scandium/gold (Sc/Au), with a low Schottky barrier height and reduced charge scattering platform of h-BN. Further, we elucidated the Schottky-barrier-height dependent high photoresponsivity (∼3.2 × 10<sup>6</sup> A W<sup>-1</sup>) of few-layer ReSe<sub>2</sub> (FL-ReSe<sub>2</sub>) at 532 nm-wavelength laser light on an h-BN substrate with Sc/Au contacts. Moreover, broadband light detection of undoped and Co-doped few-layer (FL) ReSe<sub>2</sub> was performed under different laser wavelengths (400-1100 nm). After the deposition of Co nanoparticles, the photocurrent of FL-ReSe<sub>2</sub> increased due to n-doping, as confirmed by the transfer curves of the FL-ReSe<sub>2</sub>-based undoped and co-doped FETs. Further, the work function decreased from 4.856 to 4.791 eV in FL-ReSe<sub>2</sub>, as measured by Kelvin probe force microscopy. No light signal was observed at 1100 nm for the undoped ReSe<sub>2</sub> (1050 nm < λ <sub>cut-off</sub> < 1100 nm); however, after doping with Co nanoparticles, the cut-off wavelength exceeded to (λ <sub>cut-off</sub> > 1100 nm), due to the additional trap states generated in the energy band gap of ReSe<sub>2</sub> after Co doping. Further, the transient response of ReSe<sub>2</sub> and Co + ReSe<sub>2</sub> FETs was estimated so that the rise and decay times are decreased from 1.9 s & 2.7 s to 1.1 s & 1.8 s, respectively. ReSe<sub>2</sub> is therefore a promising semiconducting material for electrical and optoelectrical applications.</p>}},
author = {{Khan, Muhammad Farooq and Rehman, Shania and Akhtar, Imtisal and Aftab, Sikandar and Ajmal, Hafiz Muhammad Salman and Khan, Waqar and Kim, Deok Kee and Eom, Jonghwa}},
issn = {{2053-1583}},
keywords = {{high responsivity; photodetector; rhenium diselenide; Schottky barrier height; transition metal dichalcogenides}},
language = {{eng}},
number = {{1}},
publisher = {{IOP Publishing}},
series = {{2D Materials}},
title = {{High mobility ReSe<sub>2</sub> field effect transistors : Schottky-barrier-height-dependent photoresponsivity and broadband light detection with Co decoration}},
url = {{http://dx.doi.org/10.1088/2053-1583/ab4ef4}},
doi = {{10.1088/2053-1583/ab4ef4}},
volume = {{7}},
year = {{2020}},
}