Short-time thermal formation of transparent and conductive SWCNT/SiO ₂ composite thin films using molecular precursor method

Single-walled carbon nanotube (SWCNT)/SiO 2 composite thin films were fabricated using short-time heat treatment of molecular precursor films spin-coated onto soda-lime glass substrates. They exhibited mechanical durability exceeding a pencil hardness of 6H at heating temperatures between 100 and [Formula: see text]C, regardless of the SWCNT concentration in the mixed precursor solution, which was varied from 0.02 to 0.12 mmol g[Formula: see text]. The sheet resistance of the composite thin films decreased significantly when the heating temperature exceeded [Formula: see text]C and the heating time exceeded 10 min. The percolation threshold for the sheet resistance of the composite thin films with respect to the SWCNT volume concentration was between 3.0 and 6.3 vol.%. In addition, the transmittance at 550 nm remained above 80% up to a concentration of 14.5 vol.%. Composite thin films containing 14.5 vol.% SWCNT heated at [Formula: see text]C for 10 min exhibited the lowest sheet resistance (0.6 k[Formula: see text] sq[Formula: see text] and the highest figure of merit, taking transmittance into account. Scanning electron microscopy and Raman spectroscopy indicated that the SWCNT bundles maintained their crystallinity under the processing conditions, forming an interconnected network without significant SWCNT degradation.