ZnTe, CdTe, and the ternary alloy CdZnTe are important semiconductor materials used widely for the detection of an important range of electromagnetic radiation as gamma ray and X-ray. Although, recently these material...ZnTe, CdTe, and the ternary alloy CdZnTe are important semiconductor materials used widely for the detection of an important range of electromagnetic radiation as gamma ray and X-ray. Although, recently these materials have acquired renewed importance due to the new explored nanolayer properties of modern devices. In addition, as shown in this work they can be grown using uncomplicated synthesis techniques based on the deposition in vapour phase of the elemental precursors. This work presents the results obtained from the deposition of nanolayers of these materials using the precursor vapour on GaAs and GaSb (001) substrates. This growth technique, extensively known as atomic layer deposition (ALD), allows the layers growth with nanometric dimension. The main results presented in this work are the used growth parameters and the results of the structural characterization of the layers by the means of Raman spectroscopy measurements. Raman scattering shows the peak corresponding to longitudinal optical (LO)-ZnTe, which is weak and slightly redshift in comparison with that reported for the ZnTe bulk at 210 cm^-1. For the case of the CdTe nanolayer, Raman spectra presented the LO-CdTe peak, which is indicative of the successful growth of the layer. Its weak and slightly redshift in comparison with that reported for the CdTe bulk can be related with the nanometric characteristic of this layer. The performed high-resolution X-ray diffraction (HR-XRD) measurement allows to study some important characteristics such as the crystallinity of the grown layer. In addition, the HR-XRD measurement suggests that the crystalline quality has dependence on the growth temperature.展开更多
The Cd1-xZnxTe（CZT） single crystals were annealed by a two-step method including a vapor-environment step and a liquid-environment step in sequence. The effects of annealing on the properties of CZT were analyzed in...The Cd1-xZnxTe（CZT） single crystals were annealed by a two-step method including a vapor-environment step and a liquid-environment step in sequence. The effects of annealing on the properties of CZT were analyzed in detail. IR transmission measurement results show that IR transmission of CZT is improved dramatically after annealing. X-ray rocking curves indicate that the annealing treatment ameliorates crystal quality obviously, which is ascribed to the release of residual stress and the reduction of point defects. Photoluminescence（PL） spectra reveal that the full width at half maximum（FWHM） of the donor-bound exciton （D0, X） peak is reduced obviously, and the free exciton emission is weakened after annealing. Meanwhile, the intensity of the donor-acceptor pair（DAP） peak decreases to a great degree, which implies that the impurities are removed from CZT wafers. In addition, the deep defect-related emission band Dcomplex disappears after annealing, which mean that Cd vacancies are well-compensated. The results confirm that the two-step annealing is an effective approach to improve the qualities of CZT single crystals.展开更多
文摘ZnTe, CdTe, and the ternary alloy CdZnTe are important semiconductor materials used widely for the detection of an important range of electromagnetic radiation as gamma ray and X-ray. Although, recently these materials have acquired renewed importance due to the new explored nanolayer properties of modern devices. In addition, as shown in this work they can be grown using uncomplicated synthesis techniques based on the deposition in vapour phase of the elemental precursors. This work presents the results obtained from the deposition of nanolayers of these materials using the precursor vapour on GaAs and GaSb (001) substrates. This growth technique, extensively known as atomic layer deposition (ALD), allows the layers growth with nanometric dimension. The main results presented in this work are the used growth parameters and the results of the structural characterization of the layers by the means of Raman spectroscopy measurements. Raman scattering shows the peak corresponding to longitudinal optical (LO)-ZnTe, which is weak and slightly redshift in comparison with that reported for the ZnTe bulk at 210 cm^-1. For the case of the CdTe nanolayer, Raman spectra presented the LO-CdTe peak, which is indicative of the successful growth of the layer. Its weak and slightly redshift in comparison with that reported for the CdTe bulk can be related with the nanometric characteristic of this layer. The performed high-resolution X-ray diffraction (HR-XRD) measurement allows to study some important characteristics such as the crystallinity of the grown layer. In addition, the HR-XRD measurement suggests that the crystalline quality has dependence on the growth temperature.
基金Project(50336040) supported by the National Natural Science Foundation of China
文摘The Cd1-xZnxTe（CZT） single crystals were annealed by a two-step method including a vapor-environment step and a liquid-environment step in sequence. The effects of annealing on the properties of CZT were analyzed in detail. IR transmission measurement results show that IR transmission of CZT is improved dramatically after annealing. X-ray rocking curves indicate that the annealing treatment ameliorates crystal quality obviously, which is ascribed to the release of residual stress and the reduction of point defects. Photoluminescence（PL） spectra reveal that the full width at half maximum（FWHM） of the donor-bound exciton （D0, X） peak is reduced obviously, and the free exciton emission is weakened after annealing. Meanwhile, the intensity of the donor-acceptor pair（DAP） peak decreases to a great degree, which implies that the impurities are removed from CZT wafers. In addition, the deep defect-related emission band Dcomplex disappears after annealing, which mean that Cd vacancies are well-compensated. The results confirm that the two-step annealing is an effective approach to improve the qualities of CZT single crystals.
基金Projects (61274081, 50902113, 50902114) supported by the National Natural Science Foundation of ChinaProject (2011CB610406) supported by the National Basic Research Program of China+2 种基金Project (B08040) supported by the 111 Project of ChinaProject (JC20100228) supported by Foundation for Fundamental Research of Northwestern Polytechnical University (NPU), ChinaProject (SKLSP201012) supported by the Research Fund of the State Key Laboratory of Solidification Processing (NPU), China
