Preferential grain growth, tunable bandgap and topological insulating to bulk state modification induced via Ag ion irradiation in antimony telluride nanostructured thin film. (January 2023) - Rahman, Raja Saifu
Abstract: Ion irradiation has been an important technique to alter the physical properties of materials for desired applications. Sb2 Te3 thin films deposited via vacuum thermal evaporation procedure are Ag ion irradiated at various fluences. Preferential grain growth along the [104] direction and reduction in optical bandgap from 1.37 eV for unirradiated thin films to 1.14 eV for irradiated thin films is noticed. The value of the Seebeck coefficient decreases with ion fluences 1 × 10 10 and 1 × 10 12 ions/cm 2 owing to the variation in carrier concentration as evident from the Hall measurements. Interestingly, the value of the Seebeck coefficient of the pristine film (457 μV/K at 313 K) is higher than previously reported value in these materials. The study might be catchy to tailor the physical properties of alloys for thermophotovoltaic applications. Highlights: Facile thermal evaporation technique is employed to deposit nanostructured Sb2 Te3 thin films. Ion irradiation induced structural changes (orientational crystal order) was investigated. Decrease in bandgap with increase in ion fluence is noticed. Enhanced Seebeck coefficient is attained in the investigated thin films.