Abstract
The contactless modulation spectroscopy technique of photoreflectance (PR) has been used to study the near band edge transitions in CdTe, CdTe:V and CdTe:Ge bulk crystals in the range of 14 and 400 K for the first time. The lineshape of the PR spectra for the crystals is seen to follow the third derivative functional form (TDFF) of electroreflectance (ER) in the low field limit. Using the line shape analysis of the spectra at different temperatures, the variation of band gap ( E 0), phase factor ( θ) and energy broadening parameter. (Γ) with temperature are studied. The temperature variation of band gap for these crystals is seen to follow the Varshni relation with coefficient values α = 4.357 × 10 −4 eV K −1, β = 183.4 K for undoped, α = 4.635 × 10 −4 eV K −1, β = 184.5 K for vanadium-doped and α = 4.508 × 10 −4 eV K −1, β = 230.5 K for Ge doped crystals. The Varshni relation is found to be valid for the whole range of temperature studied for undoped and Ge-doped crystals, where as for V-doped crystals, Varshni relation is valid upto about 250 K. Effects of vanadium and germanium doping on the energy broadening parameter in CdTe are discussed.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
