Optical properties of transparent and heat-reflecting indium tin oxide films: Refinements of a model for ionized impurity scattering

Abstract

We compute the dynamic resistivity ρ≡ρ₁+iρ₂ for a model of heavily n‐doped semiconductors with special regard to transparent and heat‐reflecting In₂O₃:Sn films. The Sn impurities are ionized and the ensuing electrons occupy part of the In₂O₃ conduction band as a free‐electron gas (with plasma energy ℏω_p). We use pseudopotential arguments to show that the Sn ions act as Coulomb scatterers up to the largest electron densities of practical interest. By representing screening in the electron gas with different models, it was found that exchange and correlation could decrease ρ₁ by ≲20% below ℏω_p and alter the exponent s in the relation ρ₁∝ω^s, applying at ℏω>ℏω_p, from −3/2 to ∼ −2.