A novel method of introducing PbO dopant and (the study of) its influence on the electrical properties of semiconducting Cd_2−x Pb _x SnO₄ thick films

Abstract

The sheet resistance of Cd₂SnO₄ thick films was reduced from 15580 to 0.09 kΩ with respect to dopant concentration and peak firing temperature (600 to 900° C). Distinct colour changes were observed in these films. The inorganic binder introduced an impurity which greatly induce changes in its electrical properties. The Arrhenius relation (logR−10³/T) generally indicated slopes of 2 to 3 for all the compositions of Cd_2−x Pb _x SnO₄ (x=0.002, 0.01, 0.02, 0.04 and 0.1). The donor ionization energies (E _d) varied from 0.01 to 0.76 eV. Resistance measurements during heating-cooling cycles indicated the possible presence of structural defects such as oxygen vacancies and cadmium interstitials. The oxidation of dopant (Pb²⁺→Pb⁴⁺+2e′) contributed in a major way to the overall conductivity. Scanning electron micrographs showed a progressive network formation due to sintering, thus contributing to the carrier mobility.