title: Impurity-dependent photoresponse properties in single CdSe nanobelt photodetectors.
abstract: Impurity-dependent photoresponse properties of semiconductor nanostructures are studied for the first time in the photodetectors (PDs) made from intrinsic (i-) and extrinsic n-type single CdSe nanobelts (NBs). Both ohmic and Schottky contact based CdSe NB PDs were studied. The sizes of i- and n- NBs were purposely chosen to be nearly identical to minimize the size-dependent effect. Our experimental results demonstrate that i-CdSe NBs are more suitable for fast and sensitive PD applications, while n-CdSe NBs are more advantageous for high-gain PD applications. The different photoresponse properties result mainly from the impurity induced traps inside the CdSe NBs. This conclusion can be applicable to other semiconductor nanomaterials. Moreover, we have achieved short response/recovery times (∼15/31 μs) and a high photosensitivity (∼100) simultaneously from the i-CdSe NB PDs under a 3500 Hz pulsed illumination. This may be the best reported result so far in the effort of getting fast speed and high photosensitivity simultaneously from nanostructure based PDs for practical applications.
authors.affiliation: State Key Lab for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871, China.
authors.forename: Peicai
authors.initials: P
authors.lastname: Wu
authors.forename: Yu
authors.initials: Y
authors.lastname: Dai
authors.forename: Tuo
authors.initials: T
authors.lastname: Sun
authors.forename: Yu
authors.initials: Y
authors.lastname: Ye
authors.forename: Hu
authors.initials: H
authors.lastname: Meng
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Fang
authors.forename: Bin
authors.initials: B
authors.lastname: Yu
authors.forename: Lun
authors.initials: L
authors.lastname: Dai
mesh_terms: D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010777:Photochemistry / Q000379:methods*; D012666:Semiconductors; D013440:Sulfides / Q000737:chemistry; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D013440:Sulfides; D017967:Zinc Compounds; C031238:zinc sulfide