Generally acceptor doped Semiconductor (Ag or Sb doped CdTe ) gives red shift being p type material.
How ever I am observing blue shift in my sample which is p type CdTe.
So Burstein - Moss blue shift approach does not fit in this case.
What can be the other reason for blue shift in absorption spectra in the p-type CdTe?
It is well established phenomena of nano-crystalline CdTe film; The UV–VIS spectra of this film shows a blue shift in absorption due to quantum confinement effect for the small crystal size.
Stable p-type conduction in ZnO has been a long time obstacle in utilizing its full potential such as in opto-electronic devices. We designed a unique experimental set-up in the laboratory for high Na-doping by thermal diffusion in the bulk ZnO single crystals. SIMS measurement shows that Na concentration increases by 3 orders of magnitude, to ~3 × 1020 cm−3 as doping temperature increases to 1200 °C. Electronic infrared absorption was measured for Na-acceptors. Absorption bands were observed near (0.20–0.24) eV. Absorption bands blue shifted by 0.04 eV when doped at 1200 °C giving rise to shallow acceptor level. NaZn band movements as a function of doping temperature are also seen in Photoluminescence emission (PL), Photoluminescence excitation (PLE) and UV-Vis transmission measurements. Variable temperature Hall measurements show stable p-type conduction with hole binding energy ~0.18 eV in ZnO samples that were Na-doped at 1200 °C.
At higher dopant concentration it can be due to Burstein moss effect: Please see following video:
https://www.youtube.com/watch?v=bferh8TyA-Y
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