Quantum size effect on cubic PbTe nanocrystals embedded in amorphous InSe thin film matrix

• Cubic PbTe nanocrystals have been embedded in amorphous InSe quantum wells.
• Simple vacuum deposition was used to embed PbTe NCs with good periodicity.
• TEM cross section shows cubic PbTe NCs within amorphous InSe interfaces.
• XRD profile indicates diffraction from quantum confined PbTe NCs within InSe.
• Quantum size effect was revealed by the blue shift in optical absorption spectra.

PbTe nanocrystals (NCs) embedded in a multilayered structure with amorphous InSe has been prepared and investigated. PbTe/InSe multilayered structures composed of alternating InSe and PbTe layers were prepared with different numbers of PbTe NCs layers by thermal evaporation technique. The presence of cubic PbTe NCs was confirmed from transmission electron microscopy images of the film cross section. High resolution X-ray diffraction characterization demonstrated face centered cubic rock salt structure of PbTe and the average size of PbTe NCs are varied by the number of PbTe NCs layers. Quantum size effect was revealed by the blue shift in the absorption edges of the multiple PbTe NCs layers structure with respect to the reference PbTe films. The experimentally observed absorption edge shift is compared with the theoretical values predicted based on the effective mass approximation model.

Cubic Lead Telluride (PbTe) nanocrystals embedded in amorphous InSe thin films by thermal evaporation technique (a). Crystallographic orientation of PbTe with (2 2 0) plane with the absence of InSe matrix peak.Figure optionsDownload as PowerPoint slide