Assembly of one-dimensional nanorods into Bi2S3 films with enhanced thermoelectric transport properties

Bismuth sulfide thin films have been assembled by cross-linkage nanorods on surface-functionalized Si substrate with self-assembled monolayers. Results of transmission electron microscopy and electron diffraction revealed that highly crystalline Bi2S3 nanorods grow along c-axis direction. Electrical transport properties including resistivity (0.02 Omega cm), thermopower (-755 mu V K-1), and carrier mobilities (1100 cm(2) V-1 s(-1)) of the Bi2S3 films at 300 K are found superior to those of previously reported Bi2S3 samples. The Bi2S3 films exhibit a maximum thermoelectric power factor (3.97x10(-3) W m(-1) K-2) at 450 K. The enhancement of thermoelectric properties mainly originates from highly crystalline and oriented nanostructures embedded in the Bi2S3 films. (c) 2007 American Institute of Physics.