title: Optoelectronic properties of CdSe0.75S0.25 nanocrystals assembled into micro-electrodes.
abstract: CdSe0.75S0.25 semiconductor nanocrystals were synthesized by chemical colloidal route. The crystal structure, morphology and optical properties of synthesized CdSe0.75S0.25 nanocrystals were characterized by XRD, TEM and UV-Vis absorption spectroscopy respectively. The crystal structure of CdSe0.75S0.25 is face-centered Cubic sphalerite phase. The average size is about 7 nm in diameter. A gold tip-to-tip structure electrode with the gap size -20 microm was fabricated using conventional optical lithography technique followed by film deposition and standard lift-off process. An optoelectronics device was fabricated based on CdSe0.75S0.25 by assembling nanocrystals into electrodes by using dielectrophoresis (DEP) process. The electrical transport properties and opto-electrical transport properties of the fabricated device were measured at temperature range from 5 K to 305 K. The results show that the resistance of CdSe0.75S0.25 NCs increases with the temperature decreases, indicating a typical semiconductor behavior. An obvious photoconductive behavior was observed, demonstrated potential application in nano-optoelectronics devices. After data analyzing, the conductivity shows the 0.5 exponent of Efros-Shklovskii variable-range-hopping (ES-VRH) model.
authors.affiliation: Department of Physics, Center for Optoelectronics Materials and Devices, Zhejiang Sci-Tech University, Hangzhou 310018, PR China.
authors.forename: Y H
authors.initials: YH
authors.lastname: An
authors.forename: Y
authors.initials: Y
authors.lastname: Xing
authors.forename: J
authors.initials: J
authors.lastname: Song
authors.forename: P G
authors.initials: PG
authors.lastname: Li
authors.forename: S L
authors.initials: SL
authors.lastname: Wang
authors.forename: A P
authors.initials: AP
authors.lastname: Liu
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Zhu
authors.forename: W H
authors.initials: WH
authors.lastname: Tang