Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Morphological

Preparation and Characterization Study of Porous Silicon Doped with Cu and Ag

U. M. Nayef; A.M. Abdul Hussein; A. J. Kata

Engineering and Technology Journal, 2017, Volume 35, Issue 1, Pages 8-12

In this paper, porous silicon was prepared by using electrochemical etching technique of p-type silicon acceptor, with a resistivity of, using hydrochloric acid with concentration of 24%. The etching current density effect 4, 12, 20mA/cm2 was carried out at constant etching time of 15min. The structural characteristics of the porous silicon and the doped porous silicon were studied and found an expansion in the spectrum of the X-rays and a simple shift in the diffraction angles while maintaining the surface direction (111). The morphological properties were studied using the atomic force microscope which showed pores formation and gives the pore diameter within the range of 19.08 to 44.73nm for the prepared samples. It was also noted that the rate of pore diameter and the thickness of the porous silicon layer increased with increasing etching current density. Electrical characteristics of the nanoscale porous silicon layer and the doped porous silicon with silver and copper showed that Current-Voltage (I-V) characteristics of the prepared samples to be a rectifying behavior. An improvement in the electrical characteristics of the doped porous silicon samples was observed

Characteristics Study of ZnO Thin Films by Rapid Thermal Oxidation Treatment Technique

Uday Muhsin Nayef; Mohammed Jamal Jasim

Engineering and Technology Journal, 2015, Volume 33, Issue 1, Pages 37-44

In this paper preparation of good quality transparent conductive ZnO thin films by post-oxidation of vacuum evaporated Zn, on glass and silicon (p-type) as substrates, the oxidation was achieved in a short time (90 sec) which is known as rapid thermal oxidation. One growth parameter has been considered to specify the optimum conditions the film thickness are (200,300,400 &500 nm).
The XRD spectra revealed a high oriented grain in the (002) lattice system which is hexagonal wurtzite and proved that the ZnO films have a polycrystalline structure. Also, the morphological properties of ZnO films show that all films have a homogeneous surface morphology and it appears, to change significantly as a function of thickness.The energy gap of ZnO films decreases as the thickness increases. The FTIR spectra indicate the existence of the distinct characteristic absorption peak at 472.56cm-1 for Zn-O stretching mode.
Study of effect I-V and C-V measurements of ZnO films with the increase thickness. The photovoltaic properties confirmed that the photovoltaic depends strongly on the bias voltage and the amount of current produced by a photovoltaic device which is directly related to the number of photons absorbed. C-V results demonstrated that the fabricated heterojunction is of abrupt type. Also, the width of the depletion layer (w) follows the same behavior (V_bi ) decreased while the charge carrier density (N_d ) was increased with the thickness increase.

Optical and Morphological Property of Ag Nanoparticles by Laser Ablation in Double Distilled and Deionized Water

Amenah Ali Salman

Engineering and Technology Journal, 2014, Volume 32, Issue 5, Pages 938-942

Noble metal silver NPs was synthesized by pulsed (Q-switched, 1064 nm Nd : YAG) laser ablation of silver metal plates immersed in double distilled and deionized water DDDW.
The formation efficiency of PLAL process was quantified in term of the surface Plasmon extinction SPE peaks. The SPE spectra show a sharp and single peak around 400 nm, indicating the production of pure and spherical Ag.
UV-Visible absorption results confirmed formation of silver particles prepared and atomic force microscope (AFM) indicates the size in nanometer (nm) range.