Post-delay-time dependences of the formation of CdTe/ZnTe nanostructures and their activation energies

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Atomic force microscopy (AFM) and photoluminescence measurements were carried out to investigate both the formation of CdTe/ZnTe nanostructures and their electron activation energies for various delay times between the deposition of the CdTe layer and the introduction of nitrogen gas into the same chamber. The AFM images show that CdTe quantum dots (QDs) are formed. While the excitonic peak associated with the transition from the ground electronic subband to the ground heavy-hole band (E1-HH1) shifted to higher energy with increasing thickness of the CdTe thin film up to delay time of 10 s, it shifted to lower energy with an increasing thickness of the CdTe thin film for delay times from 20 to 60 s. The activation energy of the electrons confined in the 3.5 ML CdTe QDs grown with a delay time of 5 s was higher than it was for the electrons in CdTe nanostructures grown with delay times of 0 and 60 s. The present results can help to improve the understanding of how the formation of and the electron activation energy in CdTe/ZnTe nanostructures depend on the delay time.