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Papers by hakim haoues
Optik, 2018
Porous silicon (PS) has been prepared from n-type (100) silicon substrate by using electrochemica... more Porous silicon (PS) has been prepared from n-type (100) silicon substrate by using electrochemical etching under He-Ne laser illumination. The PS was produced within several etching conditions. The morphological, structural and optical properties were studied by using atomic force microscopy (AFM), X-ray diffraction (XRD), Raman analysis, and reflectance measurements. Results show that the evolution of the obtained nanostructures is strongly related to anodization conditions. The optical analysis results show that a low reflectance was obtained for samples anodized by increasing current density. This is correlated to morphological results showing the strong dependence of the obtained nanoporous structure in terms of crystallites sizes and porosity, on the anodization conditions.
Materials Science in Semiconductor Processing, 2013
Silicon nanocrystals have been produced by thermal annealing of SiNx thin film obtained by low pr... more Silicon nanocrystals have been produced by thermal annealing of SiNx thin film obtained by low pressure chemical vapor deposition using a mixture between disilane and ammonia. Morphological, structural, and photoluminescence properties of the thin film were investigated using X-ray diffraction, scanning electron microscopy, Raman spectroscopy and photoluminescence spectroscopy. The results revealed a high crystallinity of film with a crystalline volume fraction exceeded 70 %, and a dominance of silicon nanocrystallites having the sizes within the range 2.5-5 nm and density ~1.98.10 12 /cm 2. The PL peaks consist of nanocrystalline silicon and amorphous silicon. The luminescence from the silicon nanocrystals was dominant.
Acta Physica Polonica A, 2012
In this work we will investigate the size distribution of the amorphous silicon quantum dots (Si-... more In this work we will investigate the size distribution of the amorphous silicon quantum dots (Si-AQD) inside a silicon nitride film SiNx (x = 0.12). The studied film contains an ensemble of silicon nanocrystals (Si-nc) inside an amorphous silicon nitride matrix SiNy (y = 0.66). Since the nitrogen atoms number are less than the silicon atoms number in the amorphous matrix, we can suggest that silicon atoms can aggregate under amorphous quantum dots. In this context, we will first estimate the number of crystallized silicon atoms (c-Si). The number of amorphous silicon atoms (a-Si) can be deduced from the fraction of crystallized silicon atoms and leads to the determination of the number of nitrogen atoms. Results show that all the nitrogen atoms are localized in the Si-ncs cap shell. Thus, the amorphous quantum dots can be easily revealed from the scattering electron microscopy (SEM) image. The low yield of luminescence from amorphous quantum dots can explain the difference between b...
Optik, 2018
Porous silicon (PS) has been prepared from n-type (100) silicon substrate by using electrochemica... more Porous silicon (PS) has been prepared from n-type (100) silicon substrate by using electrochemical etching under He-Ne laser illumination. The PS was produced within several etching conditions. The morphological, structural and optical properties were studied by using atomic force microscopy (AFM), X-ray diffraction (XRD), Raman analysis, and reflectance measurements. Results show that the evolution of the obtained nanostructures is strongly related to anodization conditions. The optical analysis results show that a low reflectance was obtained for samples anodized by increasing current density. This is correlated to morphological results showing the strong dependence of the obtained nanoporous structure in terms of crystallites sizes and porosity, on the anodization conditions.
Materials Science in Semiconductor Processing, 2013
Silicon nanocrystals have been produced by thermal annealing of SiNx thin film obtained by low pr... more Silicon nanocrystals have been produced by thermal annealing of SiNx thin film obtained by low pressure chemical vapor deposition using a mixture between disilane and ammonia. Morphological, structural, and photoluminescence properties of the thin film were investigated using X-ray diffraction, scanning electron microscopy, Raman spectroscopy and photoluminescence spectroscopy. The results revealed a high crystallinity of film with a crystalline volume fraction exceeded 70 %, and a dominance of silicon nanocrystallites having the sizes within the range 2.5-5 nm and density ~1.98.10 12 /cm 2. The PL peaks consist of nanocrystalline silicon and amorphous silicon. The luminescence from the silicon nanocrystals was dominant.
Acta Physica Polonica A, 2012
In this work we will investigate the size distribution of the amorphous silicon quantum dots (Si-... more In this work we will investigate the size distribution of the amorphous silicon quantum dots (Si-AQD) inside a silicon nitride film SiNx (x = 0.12). The studied film contains an ensemble of silicon nanocrystals (Si-nc) inside an amorphous silicon nitride matrix SiNy (y = 0.66). Since the nitrogen atoms number are less than the silicon atoms number in the amorphous matrix, we can suggest that silicon atoms can aggregate under amorphous quantum dots. In this context, we will first estimate the number of crystallized silicon atoms (c-Si). The number of amorphous silicon atoms (a-Si) can be deduced from the fraction of crystallized silicon atoms and leads to the determination of the number of nitrogen atoms. Results show that all the nitrogen atoms are localized in the Si-ncs cap shell. Thus, the amorphous quantum dots can be easily revealed from the scattering electron microscopy (SEM) image. The low yield of luminescence from amorphous quantum dots can explain the difference between b...