Organic tris͑8-hydroxyquinoline͒aluminum ͑Alq3͒ amorphous layers are prepared by vacuum deposition at various substrate temperatures T sub from 30 to 180°C. The surface morphology and electrical characteristics of these as-deposited layers are studied by atomic force microscopy and current-density versus electric-field ͑J-E͒ curves. The temperature dependence of the dark electrical conductivity ͑T͒ determined from J-E curves is also examined. These experimental results reveal that the surface and electrical properties of Alq3 amorphous layers deposited at T sub between 90 and 120°C exhibit an anomalous T sub dependence. However, this anomalous T sub dependence is not observed from infrared absorption measurements, and therefore is not the result of chemical degradation. The observed behavior is explained in terms of the property that the vacuum deposition of Alq3 with T sub between 90 and 120°C involves a thermal interconversion between meridional and facial Alq3 isomers.

In this study, various Alq 3 amorphous layers are prepared by vacuum deposition at different substrate temperatures T sub . The surface morphology, structural information, and electrical and optical properties of these as-deposited layers are studied by atomic force microscopy, X-ray diffraction, J-E curves, and photoluminescence studies, respectively. The optimum deposition conditions for Alq 3 amorphous layers with respect to T sub are also discussed.

A silver nano-tripod (AgNT) structure with a high-density “hot spots” distribution was fabricated by a tilting angle deposition technique. The electric field simulation distribution showed that the electric field enhancement of the AgNT structures is optimal when the tilting angle is 72°. Such AgNT substrates were successfully obtained experimentally when the included angle between the silver vapor and the normal of the sample platform was set to 86°. R6G and CV were used as probe molecules to investigate the SERS activity of AgNT, which revealed that the detection limits of AgNT for R6G and CV were 2.24×10−8 M and 4.01×10−8 M, the relative standard deviations (RSDs) were 4.26% and 4.44%, and the enhancement factors (EFs) were 9.58×106 and 1.16×107, respectively. The AgNT substrates with simple preparation and high distribution density of “hot spots” illustrate a good application prospect in environmental monitoring.

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