Resonant nature of intrinsic defect energy levels in PbTe revealed by infrared photoreflectance spectroscopy

Journal Article · Mon Jul 14 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4890621· OSTI ID:22311082

Zhang, Bingpo; Cai, Chunfeng; Jin, Shuqiang; Ye, Zhenyu; Wu, Huizhen ^[1]; Qi, Zhen ^[2]

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1. Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou, Zhejiang 310027 (China)
2. National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China)

Step-scan Fourier-transform infrared photoreflectance and modulated photoluminescence spectroscopy were used to characterize the optical transitions of the epitaxial PbTe thin film grown by molecular beam epitaxy on BaF{sub 2} (111) substrate in the vicinity of energy gap of lead telluride at 77 K. It is found that the intrinsic defect energy levels in the electronic structure are of resonant nature. The Te-vacancy energy level is located above the conduction band minimum by 29.1 meV. Another defect (V{sub X}) energy level situated below valance band maximum by 18.1 meV is also revealed. Whether it is associated with the Pb vacancy is still not clear. It might also be related to the misfit dislocations stemming from the lattice mismatch between PbTe and BaF{sub 2} substrate. The experimental results support the theory prediction (N. J. Parada and G. W. Pratt, Jr., Phys. Rev. Lett. 22, 180 (1969), N. J. Parada, Phys. Rev. B 3, 2042 (1971)) and are consistent with the reported Hall experimental results (G. Bauer, H. Burkhard, H. Heinrich, and A. Lopez-Otero, J. Appl. Phys. 47, 1721 (1976)).

• OSTI ID: 22311082
• Journal Information: Applied Physics Letters, Vol. 105, Issue 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTIVATION ENERGY
BARIUM FLUORIDES
CRYSTAL DEFECTS
DISLOCATIONS
ELECTRONIC STRUCTURE
ENERGY GAP
FORECASTING
FOURIER TRANSFORM SPECTROMETERS
LEAD TELLURIDES
MOLECULAR BEAM EPITAXY
PHOTOLUMINESCENCE
SPECTROSCOPY
SUBSTRATES
THIN FILMS
VACANCIES