Change in the Electrical Conductivity of the ITO Coating under Irradiation with an Oxygen Plasma Flow

Abstract

Transparent conductive indium tin oxide films are used in aerospace technology as conductive layers of dielectric thermal control coatings and protective glasses of solar batteries. The electrical conductivity of the surface prevents its differential electrification under the influence of charged particle flows in the Earth’s atmosphere. At the same time, the effect of space factors, including the incident flow of atomic oxygen during flight, on electrical conductivity has not been studied. In this paper, we study transparent conductive indium tin oxide coatings deposited on glass and polyimide film substrates. The effect of the incident flow of atomic oxygen was simulated by irradiating the samples with an oxygen plasma flow. The equivalent fluence of the atomic oxygen, determined by the mass loss of a polyimide film witness sample, served as a measure of the effect. Experiments have shown the effect of a 100‒3000-fold drop in the electrical conductivity of the coating as the equivalent fluence of atomic oxygen increases to 9 × 10²¹ cm^–2. Analysis of the dependence of resistance on fluence has shown that the supposed sputtering of the coating under the influence of the plasma flow is not the dominant mechanism. The probable cause of the degradation of electrical conductivity should be sought in the change in the bulk properties of the semiconductor material.