Engineering and Technology Journal

The laser ablation techniques was employed to prepare TiO2 nanoparticles by pulsed laser ablation of titanium target immersed in the double distilled deionized water using wavelength of 532nm and 1064nm of Nd:YAG laser with energy 500mJ. The as prepared products werecharacterized by X-Ray diffraction (XRD), Atomic Force Microscope (AFM) andUV-Vis spectrophotometer. The results indicate that the Tio2 nanoparticles are synthesized at room temperature and the average diameter is about (84.78, 95.96) nm to the wavelength (1064nm, 532nm) respectively. The optical study shows the nanoparticles possesses direct optical transition with band gab (3.82,3.65)to the wavelength(1064nm,532nm) respectively.Aheterojunctionphotodetectorfabricatedby drop cast film of colloidal TiO2NPs(nanoparticles) onto p-type single crystalsilicon wafer.I-V characteristics of Tio2NPs/Si heterojunction under darkand illumination conditions have been studied.

SnO2 nanoparticles were prepared by laser ablation of tin in methanol at room temperature. The particles were characterized by means of TEM, AFM, FTIR, UV-Visible absorption spectrum and electrical properties. AFM micrographs show that the obtained material is spherical nanoparticles, the size and size distribution of which depends on the experimental conditions.
From FTIR spectrum show the peak absorption of SnO2NPssuspension at 657 cm-1.
It is found that the band gap energy of SnO2NPs is higher than that of bulk SnO2 due to the decreases in the particle size according to the quantum confinement model.
From the J-V characteristics Al/SnO2 NPs/c-Si/Al hetrojunction the values of ideality factor for these devices is greater than unity which can be attributed to the recombination of electrons and holes in the depletion region as well as the tunneling effect depending on both sides of the heterojunction and on the presence of defect states.

In the present work, three different active layer thicknesses of Bi2O3 filmswas employ for fabricated n-Bi2O3/p-Si heterojunction detector, using reactive pulse laser deposition technique as preparation method, detector parameter was carried out,responsivity, detectivity quantum efficiency and rise time in order to investigated the performance of the fabricated devise

In the present work, Porous silicon constituting silicon nanostructures layer
have been produce on crystal silicon using different preparation condition in laser
induced electrical etching process. Were a (800 nm) , (1watt) semiconductor laser
has been used with the electrochemical etching process to prepare the porous layer
on the surface of (111) n- type silicon substrate. Two different Silicon resistivities
of (0.564,4.29) W.cm was employed to prepared (Ps/ Si) heterojunction at different
preparation condition. The characteristic of the prepared device has been found to
depend directly on the formation current density and substrate resistivity. The
obtained device has good parameter to work as a detector in the (V- NIR) region .

In the present paper CdO/Si heterojunction has been prepared by spray pyrolysis
method , electrical characteristics include I-V , C-V , were studied the build-inpotential
equal 1.7 eV and optoelectronic characteristics include I-V illumination
condition, photovoltaic, responsivity , quantum efficiency were studied . the
ideality factor to be 2.93 and short circuit photocurrent 170μA, open circuit
photovoltge 120mV at AM1 condition and two peaks responsivity were found ,
first peak at region 600±20nm this peak due to absorb of light in CdO through
band-to-band absorption while second region at 800±30nm which due to the Si
bandgap.

Highly (101)-oriented p-Ag2O thin film with high electrical resistivily was grown by
thermal oxidation (TO) on clean monocrystalline p-type Si without any post- deposition
annealing. From optical transmittance and absorptance data, the direct optical band gap
was found to be 1.4eV. The electrical and photovoltaic properties of Ag2O/Si isotope
heterojunction were examined in the absence of any buffer layer. Ideality factor of
heterojunction was found to be 3.9. Photoresponse result revealed that there are two peaks
located at. 750 nm and 900nm .

Highly (101)-oriented p-Ag2O thin film with high electrical resistivily
was grown by thermal oxidation (TO) on clean monocrystalline p-type Si
without any post- deposition annealing. From optical transmittance and
absorptance data, the direct optical band gap was found to be 1.4eV. The
electrical and photovoltaic properties of Ag2O/Si isotope heterojunction
were examined in the absence of any buffer layer. Ideality factor of
heterojunction was found to be 3.9. Photoresponse result revealed that there
are two peaks located at. 750 nm and 900nm .