title: High performance molybdenum disulfide amorphous silicon heterojunction photodetector.
abstract: One important use of layered semiconductors such as molybdenum disulfide (MoS2) could be in making novel heterojunction devices leading to functionalities unachievable using conventional semiconductors. Here we demonstrate a metal-semiconductor-metal heterojunction photodetector, made of MoS2 and amorphous silicon (a-Si), with rise and fall times of about 0.3 ms. The transient response does not show persistent (residual) photoconductivity, unlike conventional a-Si devices where it may last 3-5 ms, thus making this heterojunction roughly 10X faster. A photoresponsivity of 210 mA/W is measured at green light, the wavelength used in commercial imaging systems, which is 2-4X larger than that of a-Si and best reported MoS2 devices. The device could find applications in large area electronics, such as biomedical imaging, where a fast response is critical.
authors.affiliation: Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, United States.
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Esmaeili-Rad
authors.forename: Sayeef
authors.initials: S
authors.lastname: Salahuddin
mesh_terms: D004220:Disulfides / Q000737:chemistry* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008982:Molybdenum / Q000737:chemistry* / Q000528:radiation effects*; D010783:Photometry / Q000295:instrumentation*; D011829:Radiation Dosage; D012666:Semiconductors; D012825:Silicon / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D004220:Disulfides; D008982:Molybdenum; D012825:Silicon; C082964:molybdenum disulfide
references.citation: Adv Mater. 2012 Nov 14;24(43):5832-6
references.pmid: 22903762
references.citation: ACS Nano. 2012 Jan 24;6(1):74-80
references.pmid: 22165908
references.citation: Science. 2012 Jun 1;336(6085):1140-3
references.pmid: 22604723
references.citation: Pediatr Radiol. 2006 Sep;36 Suppl 2:173-81
references.pmid: 16862412
references.citation: Med Phys. 1999 Aug;26(8):1624-41
references.pmid: 10501063
references.citation: Nat Nanotechnol. 2011 Mar;6(3):147-50
references.pmid: 21278752
references.citation: Nat Commun. 2012;3:1011
references.pmid: 22910357
references.citation: Nano Lett. 2012 Sep 12;12(9):4674-80
references.pmid: 22862813
references.citation: Nano Lett. 2012 Jul 11;12(7):3695-700
references.pmid: 22681413