Hello Khaoula, if you measure the thickness (with AFM or UV-vis) and the sheet resistance (with 2 point probe or 4 point probe) you can calculate the resistivity of your film. 

Good night from México

Armando 

Is the Ito electrically conductive? You have to be careful that you are not measuring the film and the underlying ito

You could deposit a hall probe structure or circular structures on top of the film you want to measure - these structures are in the literature

Dear colleague Khaoula Ghezali

Have a nice time and good day.

Dc  Conductivity measurements

 This part deals with the detailed description of the method used for measuring the conductivity of films specimens as a function of temperature.A current source consisting of Keithley 240 A  power  supply (Es)  is connected in series with  a  known resistor  RS, generates a current  I  which  flows  through the sample of thickness 200 ± 2% nm. The  resultant  voltage drop  across the  sample  was  measured  with an  Electrometer Keithley 614 C, and the value of the sample resistance   can  be  measured. Schematic diagram for the used circuit illustrated in Fig.1.(see in the attach file)

The measurement of the electrical properties of thin films were performed at different temperatures starting from low temperature to high temperature using liquid nitrogen up to 373K. The measurements were achieved by  using cryostat  which is shown in Fig.2.(see in the attach file)The cryostat consists of an Pyrex body, having two impeded copper- constantan thermocouple and electrode terminals. The later connected to the investigated thin film sample through two isolated copper wires electrically isolated. The cryostat and its isolated cover container its  designed to fit each other  so that low vacuum could be achieved. Rubber insulator protection was supplied to prevent the fraction between the Pyrex and the container. The ambient specimen temperature could be decreased by liquid nitrogen addition to the dewar flask. A Stable constant reading of the calibrated thermocouple- placed adjacent to the sample-  could be achieved after enough suitable time. This time is the time required to get the thermal balance between the liquid nitrogen cooling and the ambient temperature. The electrical conductivity of the thin film samples at this condition  could be measured. The temperature was controlled manually and measured using digital temperature indicator. Several film specimen designs  were  used  in  the  preliminary experiments  included  gap, sandwich  and  comb  configurations. Different  metals  were examined  as  electrodes.   The results   for  the  electrical measurements were obtained using gap  specimen  design and Cu electrodes. The geometry of the film samples is shown in Fig.3 and Fig.4.(see in the attach file) All samples were deposited on ordinary glass substrate (microscope slide). A co-planar geometry was used, the inter-electrode gap of 2 mm width being obtained by using a metal mask. The gap cell geometry has been used in order to avoid the problem of the contact between the electrode and the sample, as well as avoiding the surface metal electrode transmission.  Cu  evaporation as electrodes was carried out in the same vacuum chamber used for film deposition at a pressure of  10^-5 torr.

Wishing this is useful and help you. Don't hesitate to ask about any thing about structural, electrical and optical properties.

Yours

A. El-Denglawey                      

Dear Dr. Khaoula Ghezali

Peace be upon you  السلام عليكم ورحمة الله

@A. Eldenglawey

Really, it is good description to the practical measurements of the electrical conductivity for thin film sample. All the minute aspects have been mentioned by Dr. Adel Eldenglawey.

More over, let me attach two papers concerning the electrical measurements which may help you.

Good luck

https://www.researchgate.net/publication/223793330_Optical_and_electrical_properties_of_Ge10xSe40Te50-x_thin_film

https://www.researchgate.net/publication/283421231_Electrical_transport_properties_and_Mott's_parameters_of_chalcogenide_cadmium_sulphoselenide_bulk_glasses?ev=prf_pub

Article Optical and electrical properties of Ge10+xSe40Te50−x thin film

Article Electrical transport properties and Mott's parameters of cha...

hello Armando;

thanks for the answer. Hope you are fine?

Yes, I had already measured the thickness using a profilometer (Alti surf 500)and the sheet resistance (4 point); is the obtained resistance corresponds to the deposited thin film or the ITO?

 Have a nice day from Setif :)

K GHEZALI

Dear Shahid:

thank's . Yes the ITO conductivity is 1.2*10^4 ohm/cm

Best regards 

K.GHEZALI

 Dear A. Eldenglawey;

thanks for the  discription. please accept my most distinguished greetings

K. GHEZALI

Dear  Pr. Ahmed Saeed Hassanien;

وعليكم السلام ورحمة الله وبركاته

Best Regards 

K.GHEZALI 

Hello Khaoula, the resistance you measured is a combination of  both materials, maeby you can propose an equivalent circuit because you know the conductivity of the ITO. If you apply a voltage in the ITO substrate alone and you measure the current, and then you do the same but in the ITO with your film, the difference in the currents could give you an approximation of the conductivity  of your film. 

Good luck

Armando

thanks Armando :) 

Dear colleague Khaoula Ghezali

Thanks for your kindly worm greeting.

Wishing for you all the best, Don't hesitate to ask any thing about structural, electrical and optical properties.

yours

A. EL-Denglawey 

Dear colleague Prof Dr. Ahmed Saeed Hassanien (@ Ahmed Saeed Hassanien).

Thanks for your nice compliment, it is just an atom of your knowledge.

Yours

A. El-Denglawey

thanks A. Eldenglawey

بارك الله فيك 

@A. Eldenglawey

@Khaoula Ghezali 

الأخ العزيز الأستاذ الدكتور/ عادل

الأخت العزيزة الدكتورة / خولة 

 السلام عليكم ورحمة الله وبركاته

 شكراً لكَم على كلماتكم الطيبة .. ونحن جميعاً أسرة واحدة تعمل في خدمة العلم وطلابه

أخوكم / أحمد سعيد حسنين

Dear Ghezali

ITO is a transparent conducting material.If the conductivity of your material is smaller than ITO, you can not use planar geometry for electrical measurements as you have highly conducting substrate. In such a case, you can sandwitch your film along with substrate between two electrodes to measure the conductivity. If resistance of your film is much larger as compared to substrate, then you can neglect the resistance of substrate.

A.Kumar

Dear  A. Kumar:

I had measured  the resistance using sandwich structure (Fig.01) . The problem that  I had found a high conductivity (10^3 ohm/cm) while it is too resistive materials compare with the literature. I would like to find another technique to confirm. when the conductivity of the substrate  is 10^4 ohm/cm

Dear colleague Khaoula Ghezali,

Have a nice time and good day.

you mentioned "The problem that I had found a high conductivity (10^3 ohm/cm) while it is too resistive materials compare with the literature."

there is a contradiction high conductivity (means low resistance) and (the material is too resistive compared with the literature) this means (low conductivity), this contradiction may be due to the presence of  "pin hole"  through the film. In case of "pin hole" you will get low or similar resistance with and without the film. you may need to check it .

to solve this problem clean the substrate very well and try to increase the film thickness, During electrode processing mask well the film to avoid the diffusion on the film surface which reduce the resistance.

I wish that is useful and help you to overcame this problem.

Waiting your response.

yours

A. El-Denglawey

Dear colleague A. Eldenglawey;

Have a nice time and good  day 

 thank's for the answer.

Dear Dr. Khaoula Ghezali,

السلام عليكم ورحمة الله

Indium tin oxide (ITO) is one of the most widely used transparent conducting oxides because of its two main properties, its electrical conductivity (it is about 10−4 Ohm.cm), high optical transmittance for visible light, and high near-infrared reflectance, as well as the ease with which it can be deposited as a thin film. So it is effective to be used as an n-type window layer, particularly in solar cells. 

As with all transparent conducting films, a compromise must be made between conductivity and transparency, since increasing the thickness and increasing the concentration of charge carriers will increase the material's conductivity, but decrease its transparency.

So, as you said "you had measured the resistance using sandwich structure you found it was in the order  103 (ohm.cm)-1. This mean that there is some thing error. Or may be the deposited thin film is very thin layer.

Thanks.

Dear Ahmed SAeed 

وعليكم السلام ورحمه الله و بركاته 

I have send you a message 

Best regards 

K.GHEZALI

Dear Khaoula Ghezali,

السلام عليكم ورحمة الله وبركاته

I  regret to inform you that you may have some wrong in your measurements. May be the error is due to the practical procedures. It may be one of the following:

(1) there is a pin hole  through the film, which leads to measure the resistance of the connection wires.

(2) there is a discontinuity of the film texture.

(3) The film is ultrathin, so the electrodes may touch each others.

So you must repeat your measurements after you make sure every thing is Ok.

Best regards

Ahmed Saeed Hassanien

Dear Ahmed Saeed Hassanien;0

وعليكم السلام ورحمه الله و بركاته

i will repeat the measurements,  thank you soo much 

K.GHEZALI 

Dear Khaoula Ghezali,

السلام عليكم ورحمة الله وبركاته

Good Luck and my best wishes

Don't hesitate to contact me for any assistance.

Best regards

Ahmed Saeed Hassanien

Dear Ahmed Saeed Hassanien;0

وعليكم السلام ورحمه الله و بركاته

thanks so much 

K.GHEZALI