title: A tunable photosensor.
abstract: A pyrene-modified beta-cyclodextrin (pyrenecyclodextrin)-decorated single-walled carbon nanotube (SWNT) field-effect transistor (FET) device was fabricated, which can serve as a tunable photosensor to sense a fluorescent adamantyl-modified Ru complex (ADA-Ru). When the light is on (I = 40 W m(-2) and lambda = 280 nm), the transfer curve of the pyrenecyclodextrin-SWNT/FET device shifts toward a negative gate voltage by about 1.6 V and its sheet resistance increases quickly, indicating a charge-transfer process from the pyrenecyclodextrins to the SWNTs. In contrast, the transfer curve of the pyrenecyclodextrin-SWNT/FET device in the presence of the ADA-Ru complex shifts toward a positive gate voltage by about 1.9 V and its sheet resistance decreases slowly when the light is on (I = 40 W m(-2) and lambda = 490 nm), showing a charge-transfer process from the pyrenecyclodextrin-SWNT hybrids to the ADA-Ru complex. Because these photoresponse processes are recoverable following the removal of the light, the present photosensor exhibits a promising application in the area of tunable light detection.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, California 90095, USA.
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Zhao
authors.forename: Liangbing
authors.initials: L
authors.lastname: Hu
authors.forename: George
authors.initials: G
authors.lastname: Grüner
authors.forename: J Fraser
authors.initials: JF
authors.lastname: Stoddart
mesh_terms: D005456:Fluorescent Dyes / Q000737:chemistry; D015336:Molecular Probe Techniques; D015394:Molecular Structure; D010777:Photochemistry; D017975:Ruthenium Compounds / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D017975:Ruthenium Compounds