Effect of features of the technology of polycrystalline CdTe growth on the conductivity and deep level spectrum after annealing

• Published in: Semiconductors (Woodbury, N.Y.) Vol. 48; no. 3; pp. 406 - 412
• Main Authors: Bobrova, E. A., Klevkov, Yu. V., Chernook, S. G., Senturina, N. N.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.03.2014; Springer
• Subjects: Annealing; Electric properties; Fabrication; Magnetic Materials; Magnetism; Physics; Physics and Astronomy; Testing of Materials and Structures; Treatment; CdTe Sample; DLTS Spectrum; Vacuum Sublimation; CdTe Growth; Average Deposition Rate
• ISSN: 1063-7826; 1090-6479
• DOI: 10.1134/S106378261403004X

The conductivity, morphology, and deep levels in polycrystalline CdTe are studied. Undoped p -CdTe is grown from the vapor phase by low-temperature methods of direct Cd and Te chemical reaction and CdTe vacuum sublimation at P min . Chlorine-doped CdTe is also grown. The resistivity of the grown samples is ∼105–109 Ω cm. After annealing in liquid cadmium or in cadmium vapor at ∼500°C, the conductivity type changes, the free-carrier concentration in the undoped and doped samples increases to 4 × 10 15 and ∼2 × 10 16 cm −3 , respectively. For all samples, a defect ground level of ∼0.84 eV and continuous background are observed in DLTS spectra after annealing. A correlation between the primary-defect and free-carrier concentrations in undoped and doped CdTe is observed. Chlorine is a main residual impurity in the undoped samples. It is assumed that the defect is a complex including chlorine and observed structural defects in CdTe.