Sheet resistance–temperature dependence, thermal and electrical analysis of As40S60−xSex thin films

Abstract

This framework focuses fundamentally on sheet resistance, Rs, measurements for the As40S60−xSex thin films with [(0≤ x ≥60) at.%] for thickness of the film and heating rate of 1000 nm and 5 K/min, respectively. Then, we can adapt these measurements to study the thermal and electrical properties by which we can reduce the time and effort spent. The thermal and electrical analysis in this work appears in a new format without the need for a procedure to calculate the thermal measurements from bulk material of the studied sample. The same is true for electrical properties where electrical measurements need not be necessarily carried out. In this work, we will focus first on obtaining the sheet resistance, Rs of thin films whose surface thickness is equal to 1000 nm for chalcogenide As40S60−xSex thin films with [(0≤ x ≥60) at.%] at a heating rate of 5 K/min, in the temperature range from 300 to 435 K. This range was sufficient to highlight on two important regions in the sheet resistance curve and through the derivation of sheet resistance as a function of temperature, there was clear evidence of one crystallization region for the studied samples. Second, the thermal data we obtained were used to complete the thermal calculations and then the electrical calculations. The activation energies of crystallization were evaluated. The nucleation and growth order parameter n, and the dimension order parameter m, were also computed and discussed. The activation energy, Ec, and Avrami index, n, were obtained by analyzing the data via JMA methods. The results indicated that the transformation from amorphous to crystalline phases is a complex process that includes different mechanisms of nucleation and growth. The change of activation energy with volume of crystalline fraction was determined. The crystalline phases for the as-deposited and annealed films were identified using X-ray diffraction (XRD). The electrical results of the investigated sample appear in two types of conduction channels which contribute to two conduction mechanisms in the crystallized region. In the extended and hopping states regions, the activation energies ΔE, two pre-exponential factors $$\sigma_{0} ,$$ $$\sigma_{0}^{*}$$ and other parameters were computed.