Highly Conductive Tungsten-Doped Tin(IV) Oxide Transparent Electrodes Delivered by Lattice-Strain Control

Alternatives to tin-doped indium oxide transparent electrodes are needed to meet the growing demand for modern electronic devices. Here, we present a chemical vapor deposition route to tungsten-doped SnO 2 thin films with resistivities as low as 5.9 × 10 –4 Ω cm and electron mobilities as high as 30 cm 2 V –1 s –1 . Le Bail fitting of the XRD data showed that the substitutional dopant, tungsten(V) causes minimal distortion to the SnO 2 unit cell due to its radius closely matching that of tin(IV). Furthermore, crystallographic preferential orientation in the [200] direction that is thought to facilitate a high mobility was also seen. X-ray photoelectron spectroscopy analysis suggests that W is present in the +5 state, as opposed to +6, therefore minimizing ionized impurity scattering, hence also helping achieve the observed high electron mobilities. The tungsten-doped films had optical band gaps of 3.7 eV, thus enabling transparency to visible light.