Manoeuvring Morphological, Optical and Electrical Properties of CVD-Grown Ba-Doped SnO2 Nanostructures via Mn Co-Doping

Abstract

Barium and manganese (Ba and Mn) co-doped nanostructures of tin oxide (SnO2) are synthesized in situ using a thermal chemical vapour deposition method. The structural property correlation is established using X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, ultraviolet–visible light (UV–Vis), X-ray photoelectron spectroscopy and Hall measurements. The role of substrate type (n-type silicon and quartz) and catalyst layer thickness is also studied for detailed examination of the correlation with SnO2 properties at nanoscale. In this study, the significant role of Mn as co-dopant in Ba-doped SnO2 one-dimensional and two-dimensional nanostructures (nanowires and nanoflakes) is studied. Optical and room-temperature (RT) electrical measurements confirm the band gap tailoring from 3.2 eV to 3.6 eV relating to the Ba increase with Mn as co-dopant. Subsequently, the RT electron mobility changes from 46 cm2 s−1 V−1 to 88 cm2 s−1 V−1 as SnO2 changes from Ba-doped to Ba/Mn co-doped. The effective role of the co-dopant in band gap tailoring and the effects on morphology, optical and electrical properties are studied for SnO2 nanostructures. This study helps to gain a better understanding of the dopant population and the electrical and optical properties for transparent conducting oxides (TCOs), sensors, photocatalysis, solar cell materials and other applications.