Molybdenum and tungsten doped SnO2 transparent conductive thin films with broadband high transmittance between the visible and near-infrared regions

Abstract

We demonstrate an approach for the synthesis of SnO₂ transparent conductive films with low square resistance and high transmittance over the visible and NIR regions via doping of molybdenum and tungsten. Crystallite grain agglomerations are evenly observed for each dopant, resulting in an obvious surface morphological evolution with increased doping concentration and annealing temperature. With Mo and W doping, the conductivity of doped SnO₂ samples can be efficiently enhanced by one order. Meanwhile, the electrical property of the doped SnO₂ samples sensitively responds to the doping concentration and annealing temperature due to the variation of carrier density, which even results in a square resistance of 0.26 kΩ □⁻¹ of the SnO₂:Mo:W sample. The doped samples steadily exhibit a relatively high transmittance of ∼60% over a wide wavelength range between 300 and 2500 nm, and the average transmittance of each sample is ∼2 times higher than that of ITO in the NIR region. Besides, the transmittance correspondingly increases along with the surface morphology evolution as a function of the doping concentration and annealing temperature due to light scattering.