Polymer-assisted solution processing of Mo-doped indium oxide thin films: high-mobility and carrier-scattering mechanisms

Abstract

Mo-doped indium oxide (MIO) transparent conducting films have been prepared by a polymer-assisted solution (PAS) process. Both Mo- and In-PASs have been formulated by coordinating Mo- and In-anionic complexes with polyethyleneimine. The final MIO-PAS coating solution was prepared by adding Mo-PAS and In-PAS with Mo concentration in solution ranging from 0 at% to 2.5 at%. The structural, optical and electrical properties of MIO films spin-coated on the glass substrates were characterized. The optimum Mo concentration leading to the best electrical and optical properties was 1.5 at%, showing a low resistivity of 3.9 × 10−3 Ω ⋅ cm with high mobility of 43 cm2 V−1 s−1 and high transmittance from visible to near infrared regions. The carrier-transport mechanism in the PAS-processed MIO film was investigated by applying a theoretical scattering model (Brook–Herring–Dingle theory) to Hall mobility data. The scattering model confirms that the ionized and neutral impurities play important roles as dominant scattering centers in the PAS-processed MIO films.