Pb doping of In2O3 and their conversion to highly conductive PbS/In2S3−3xO3x nanowires with infra red emission

• Pb doping of In2O3 investigated for the first time.
• Pb doped In2O3 nanowires are highly conductive and emit in the visible.
• PbS/In2S3-3xO3x nanowires obtained after processing under H2S emit in the infra red.

We have grown Pb doped In2O3 nanowires at 800 °C which have the cubic bixbyite crystal structure of In2O3 and contain orthorhombic α-PbO. These had resistances up to ≈10 Ω and exhibited photoluminescence at 2.5 eV but we observed the gradual emergence of infra red emission from 0.8 μm to 1.2 μm after processing under H2S between 200 °C and 400 °C. The resultant PbS/In2S3−3xO3x nanowires had similar resistances and consist of stacked crystals with sizes that depend on the Pb content. We discuss the potential of Pb for doping metal oxide semiconductors and the importance of PbS/In2O3 p–n tunnel junctions for solar cells.