Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Crystal and electronic structure of PbTe/CdTe nanostructures | Bukala et al. Nanoscale Research Letters 2011 6 126 http content 6 1 126 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Crystal and electronic structure of PbTe CdTe nanostructures Malgorzata Bukala1 Piotr Sankowski2 Ryszard Buczko1 Perla Kacman1 Abstract In this article the authors reported a theoretical study of structural and electronic properties of PbTe inclusions in CdTe matrix as well as CdTe nano-clusters in PbTe matrix. The structural properties are studied by ab initio methods. A tight-binding model is constructed to calculate the electron density of states DOS of the systems. In contrast to the ab initio methods the latter allows studying nanostructures with diameters comparable to the real ones. The calculations show that both kinds of inclusions lead to changes of the DOS of the carriers near the Fermi level which may affect optical electrical and thermoelectric properties of the material. These changes depend on the size shape and concentration of inclusions. Introduction PbTe is a well-known narrow-gap semiconductor. This material is widely used for mid-infrared lasers and detectors 1 2 . Moreover PbTe has attracted a lot of interest due to its thermoelectric properties and the material is used for small-scale cooling applications as well as for power generation in remote areas 3 4 . The efficiency of a thermoelectric device is described by the dimensionless thermoelectric figure-of-merit parameter ZT. In the currently used thermoelectric devices based on PbTe Si-Ge or Bi2Te3 alloys ZT reaches 1. This value imposes limitation to possible applications of semiconductor thermoelectric devices and a lot of effort is put to increase the parameter. Increased ZT values were observed in various low dimensional nanostructures like quantum wells or coupled semiconductor quantum dot QD systems of PbTe or Bi2Te3 5-7 . These observations were explained by the fact that introducing defects or nano-inclusions .
