The complex dielectric permit tivity (ε* =ε′-jε″ ) and ac conductivity (σac) of Au/SnO_(2)/n-Si(MOS) structures are studied using capacitance (C) and conductance (G(ω) ) measurements in a wide temperature range...The complex dielectric permit tivity (ε* =ε′-jε″ ) and ac conductivity (σac) of Au/SnO_(2)/n-Si(MOS) structures are studied using capacitance (C) and conductance (G(ω) ) measurements in a wide temperature range of 125-400 K for six different frequency values.It is observed that the C and G(ω) values decrease with the increasing frequency,while they increase with the increasing temperature.The observed nature of the C is due to the inability of the dipoles to orient in a rapidly varying electric field.The experimental values of the dielectric constant ε′,dielectric loss ε",loss tangent tanδ and σac are found to be strong functions of frequency and temperature.The values of the ε′ and ε″ are found to decrease with the increasing frequency and increase with the increasing temperature.The σac is found to increase with the increasing frequency and temperature.Activation energy (Ea),from the Arrhenius plot,is studied to discuss the conduction mechanism in a MOS structure.展开更多
A novel aluminum iron oxide （Al/AlFe2O4/p-Si） Schottky photodiode was successfully fabricated via the sol-gel coating process. The microstructure of the spinel ferrite （AlFe2O4） was examined by atomic force micros...A novel aluminum iron oxide （Al/AlFe2O4/p-Si） Schottky photodiode was successfully fabricated via the sol-gel coating process. The microstructure of the spinel ferrite （AlFe2O4） was examined by atomic force microscopy. The current-voltage characteristics of the fabricated photodiode were studied under dark and different illumination conditions at room temperature. By using the thermionic emission theory, the forward bias I-V characteristics of the photodiode are analyzed to determine the main electrical parameters such as the ideality factor （n） and barrier height （ФB0） of the photodiode. The values of n and ФB0 for all conditions are found to be about 7.00 and 0.76 eV, respectively. In addition, the values of series resistance （Rs） are determined using Cheung＇s method and Ohm＇s law. The values of Rs and shunt resistance （Rsh） are decreased with the increase of illumination intensity. These new spinel ferrites will open a new avenue to other spinel structure materials for optoelectronic devices in the near future.展开更多
The dielectric properties of Au/Si3N4/n-Si （MIS） structures are studied using the admittance measurements （C–V and G/ω–V） each as a function of temperature in a range from 80 K to 400 K for two frequencies （10...The dielectric properties of Au/Si3N4/n-Si （MIS） structures are studied using the admittance measurements （C–V and G/ω–V） each as a function of temperature in a range from 80 K to 400 K for two frequencies （100 kHz and 1 MHz）. Experimental results show that both the dielectric constant （ε’） and the dielectric loss （ε＂） increase with temperature increasing and decrease with frequency increasing. The measurements also show that the ac conductivity （σac） increases with temperature and frequency increasing. The lnσac versus 1000/T plot shows two linear regions with different slopes which correspond to low （120 K–240 K） and high （280 K–400 K） temperature ranges for the two frequencies. It is found that activation energy increases with frequency and temperature increasing.展开更多
文摘The complex dielectric permit tivity (ε* =ε′-jε″ ) and ac conductivity (σac) of Au/SnO_(2)/n-Si(MOS) structures are studied using capacitance (C) and conductance (G(ω) ) measurements in a wide temperature range of 125-400 K for six different frequency values.It is observed that the C and G(ω) values decrease with the increasing frequency,while they increase with the increasing temperature.The observed nature of the C is due to the inability of the dipoles to orient in a rapidly varying electric field.The experimental values of the dielectric constant ε′,dielectric loss ε",loss tangent tanδ and σac are found to be strong functions of frequency and temperature.The values of the ε′ and ε″ are found to decrease with the increasing frequency and increase with the increasing temperature.The σac is found to increase with the increasing frequency and temperature.Activation energy (Ea),from the Arrhenius plot,is studied to discuss the conduction mechanism in a MOS structure.
文摘A novel aluminum iron oxide （Al/AlFe2O4/p-Si） Schottky photodiode was successfully fabricated via the sol-gel coating process. The microstructure of the spinel ferrite （AlFe2O4） was examined by atomic force microscopy. The current-voltage characteristics of the fabricated photodiode were studied under dark and different illumination conditions at room temperature. By using the thermionic emission theory, the forward bias I-V characteristics of the photodiode are analyzed to determine the main electrical parameters such as the ideality factor （n） and barrier height （ФB0） of the photodiode. The values of n and ФB0 for all conditions are found to be about 7.00 and 0.76 eV, respectively. In addition, the values of series resistance （Rs） are determined using Cheung＇s method and Ohm＇s law. The values of Rs and shunt resistance （Rsh） are decreased with the increase of illumination intensity. These new spinel ferrites will open a new avenue to other spinel structure materials for optoelectronic devices in the near future.
基金Projected supported by Gazi University Scientific Research Project(BAP),FEF.05/2012-15
文摘The dielectric properties of Au/Si3N4/n-Si （MIS） structures are studied using the admittance measurements （C–V and G/ω–V） each as a function of temperature in a range from 80 K to 400 K for two frequencies （100 kHz and 1 MHz）. Experimental results show that both the dielectric constant （ε’） and the dielectric loss （ε＂） increase with temperature increasing and decrease with frequency increasing. The measurements also show that the ac conductivity （σac） increases with temperature and frequency increasing. The lnσac versus 1000/T plot shows two linear regions with different slopes which correspond to low （120 K–240 K） and high （280 K–400 K） temperature ranges for the two frequencies. It is found that activation energy increases with frequency and temperature increasing.
