PbSe films were chemically deposited with a range of controlled microstructures, from nanocrystalline to monocrystalline films. The crystal size in the nanocrystalline films was controlled in a range 7 to 25 nm with a fairly narrow size distribution, which allowed fine-tuning of the PbSe energy gap. The optical properties of the films were investigated using infrared (IR) transmission and IR photoluminescence measurements. The nanocrystalline PbSe films showed single bandgap values in the technologically important near-IR region. Two bandgap values, corresponding to both bulk and confined nanocrystals, were obtained for films with mixed microstructure. Strong blue shifts in both the absorption and emission peaks of the nanocrystalline layers were obtained. The bandgaps of the PbSe films were found to be in good agreement with theoretical calculations. The results point out the potential of these films for nanoscale optical device applications operating in the near-IR range.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics