Fluorine doped tin oxide SnO2:F thin films were prepared by the spray pyrolysis(SP) technique on glass substrates by using SnCl2-2H2O as a precursor and NH4F and HF as doping compounds.A comparison between the propert...Fluorine doped tin oxide SnO2:F thin films were prepared by the spray pyrolysis(SP) technique on glass substrates by using SnCl2-2H2O as a precursor and NH4F and HF as doping compounds.A comparison between the properties of the films obtained by using the two doping compounds was performed by using I-V characteristics in the dark at room temperature,AC measurements,and transmittance.It is found that the films prepared by using HF have smaller resistivity,lower impedance and they are less capacitive than films prepared by using NH4F.In addition,these films have higher transmittance,higher optical bandgap energy and narrower Urbach tail width.These results are interesting for the use of SnO2:F as forecontact in CdS/CdTe solar cells.展开更多
Indium doped cadmium sulfide thin films(CdS:In) were produced by the spray pyrolysis technique on glass substrates.AC measurements were used to investigate the electrical properties of the films depending on Brick-lay...Indium doped cadmium sulfide thin films(CdS:In) were produced by the spray pyrolysis technique on glass substrates.AC measurements were used to investigate the electrical properties of the films depending on Brick-layer model for polycrystalline materials.The measurements were performed at room temperature in the dark and room light in the frequency range from 20 Hz to 1 MHz using coplanar indium electrodes.The data were analyzed by using Bode plots for the impedance Z and dielectric loss tanδ with frequency f.It is found that the impedance has no dependence on frequency in the low frequency region but has 1/f dependence in the high frequency region.One dielectric loss peak is obtained,which means the presence of a single relaxation time,and hence the films are modeled by just one RC circuit which represents the grains.This means that there is just one conduction mechanism that is responsible for the conduction in the bulk,due to electronic transport through the grains.Real values of the impedance in the low frequency region and relaxation times for treated and as-deposited films were estimated.展开更多
文摘Fluorine doped tin oxide SnO2:F thin films were prepared by the spray pyrolysis(SP) technique on glass substrates by using SnCl2-2H2O as a precursor and NH4F and HF as doping compounds.A comparison between the properties of the films obtained by using the two doping compounds was performed by using I-V characteristics in the dark at room temperature,AC measurements,and transmittance.It is found that the films prepared by using HF have smaller resistivity,lower impedance and they are less capacitive than films prepared by using NH4F.In addition,these films have higher transmittance,higher optical bandgap energy and narrower Urbach tail width.These results are interesting for the use of SnO2:F as forecontact in CdS/CdTe solar cells.
文摘Indium doped cadmium sulfide thin films(CdS:In) were produced by the spray pyrolysis technique on glass substrates.AC measurements were used to investigate the electrical properties of the films depending on Brick-layer model for polycrystalline materials.The measurements were performed at room temperature in the dark and room light in the frequency range from 20 Hz to 1 MHz using coplanar indium electrodes.The data were analyzed by using Bode plots for the impedance Z and dielectric loss tanδ with frequency f.It is found that the impedance has no dependence on frequency in the low frequency region but has 1/f dependence in the high frequency region.One dielectric loss peak is obtained,which means the presence of a single relaxation time,and hence the films are modeled by just one RC circuit which represents the grains.This means that there is just one conduction mechanism that is responsible for the conduction in the bulk,due to electronic transport through the grains.Real values of the impedance in the low frequency region and relaxation times for treated and as-deposited films were estimated.
