Laser-based Techniques and Applications - LATA
 TPCI/NHRF
 History Infrastructure Research ERANet RU, FilmSolar ERANet-MED ENERG-11-132, HydroSol Publications WEB highlights Conferences & international Schools Awards Education Collaborations Services Technical Achievments Site on map Contact Us
 Electrical mesurements
 Conductivity measurements (I-V measurements) at RT  A. Principle of the method   We apply the van der Pauw technique to deduce the sheet resistance RS. The principle of the measurement is shown below:   RA and RB are related to the sheet resistance through the van der Pauw equation:    exp(-πRA/RS) + exp(-πRB/RS) = 1 To obtain the two characteristic resistances, one applies a dc current I into contact 1 and out of contact 2 and measures the voltage V43 from contact 4 to contact 3 as shown above. Next, one applies the current I into contact 2 and out of contact 3 while measuring the voltage V14 from contact 1 to contact 4. RA and RB are then RA = V43/I12 and RB = V14/I23   This equation can be solved numerically for RS. The bulk electrical resistivity can be calculated using ρ = RS d where d is the film thickness.     B.  Experimental setup   The experimental setup is shown in the figure below:   The electronic circuit consists of a Keithley M. 6220 DC current source and a Keithley Mo. 2182 Nanovoltmeter. Both instruments are connected to a pC via an IEEE-488 interface. The home-made sample holder consists of 4 spring probes that are mechanically pressed of the thin film sample. The probes form a quadrant with side length 10 mm (minimum sample dimensions).     C.  Example   The I-V measurement is presented for a PLD grown NiO thin film with the following deposition parameters: Glass substrate temperature 200 oC  Oxygen pressure 10 Pa.
 MO thin film development Gas sensor testing Electrical mesurements LIPS (English) LIPS (Greek)
 History Infrastructure Research ERANet RU, FilmSolar ERANet-MED ENERG-11-132, HydroSol Publications WEB highlights Conferences & international Schools Awards Education Collaborations Services Technical Achievments Site on map Contact Us