Band gap engineering in SnO2 by Pb doping

There is a growing need to lower the band gap of the transparent conductive tin oxide (SnO2) in view of its potential application in photo-electronic technology. Here, we systematically investigated the effect of Pb doping on lowering the band gap of SnO2. We demonstrate a significant reduction in its band gap to as much as ∼0.8 eV (3.64 eV-2.87 eV) upon 15% Pb doping. The observed band gap tunability with Pb-incorporation provides a direct and efficient approach to effectively tailor the band gap and is expected to open up applications in emerging oxide opto-electronic and energy applications.