We study electrical transport properties in exfoliated molybdenum disulfide (MoS2) back-gated field effect transistors at low drain bias and under different illumination intensities. It is found that photoconductive and photogating effect as well as space charge limited conduction can simultaneously occur. We point out that the photoconductivity increases logarithmically with the light intensity and can persist with a decay time longer than 104 s, due to photo-charge trapping at the MoS2/SiO2 interface and in MoS2 defects. The transfer characteristics present hysteresis that is enhanced by illumination. At low drain bias, the devices feature low contact resistance of 1.4 kW mm-1, ON current as high as 1.25 nA mm-1, 105 ON–OFF ratio, mobility of ∼1 cm2 V−1 s−1 and photoresponsivity  » 1 A W-1.

Electrical transport and persistent photoconductivity in monolayer MoS2 phototransistors

DI BARTOLOMEO, Antonio
Writing – Original Draft Preparation
;
GENOVESE, LUCA
Investigation
;
LUONGO, GIUSEPPE
Membro del Collaboration Group
;
2017-01-01

Abstract

We study electrical transport properties in exfoliated molybdenum disulfide (MoS2) back-gated field effect transistors at low drain bias and under different illumination intensities. It is found that photoconductive and photogating effect as well as space charge limited conduction can simultaneously occur. We point out that the photoconductivity increases logarithmically with the light intensity and can persist with a decay time longer than 104 s, due to photo-charge trapping at the MoS2/SiO2 interface and in MoS2 defects. The transfer characteristics present hysteresis that is enhanced by illumination. At low drain bias, the devices feature low contact resistance of 1.4 kW mm-1, ON current as high as 1.25 nA mm-1, 105 ON–OFF ratio, mobility of ∼1 cm2 V−1 s−1 and photoresponsivity  » 1 A W-1.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11386/4683085
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 152
  • ???jsp.display-item.citation.isi??? 143
social impact