Post-Synthesis Treatments for Defect Reduction in SnO₂ Aerogel for Electronic Applications

This study focuses on the synthesis and characterization of a semiconducting tin oxide (SnO₂) aerogel for electronic applications in solar cell technologies, memory devices (e.g., resistive random-access memory), and neuromorphic computing, but while bulk SnO₂ exhibits an optical bandgap energy (E_g) of around 3.6 eV, previous literature indicates that SnO₂ in aerogel form displays a larger apparent E_g of around 4.6 eV. This increase in E_g is likely attributable to defects within the material such as dangling bonds likely caused by a Burstein-Moss shift due to the Sn-rich surface. To minimize defects within the material this research characterizes the aerogels after a post-annealing process in an environment with oxygen present and the effects of using H₂O₂ as a surface treatment without a post-annealing process. This study concludes that while annealing improves some qualities of the material, this is likely due to the phase change within the material and not the reduction of defects. Whereas significant improvements in the optical characteristics using an H₂O₂ surface treatment were observed. The passivation of dangling bonds on the SnO₂ aerogel surface is the solution to minimizing the apparent E_g for future solar and neuromorphic applications.