Effect of Ag Doping on Electrical Properties Ge2Sb2Te5 Thin Films

In this work thin films of the phase change material Ge2Sb2Te5 (GST), pure and Ag-doped, were studied. These films were prepared by thermal evaporation method. Amorphous nature of both pure and Ag-doped GST thin films has been confirmed from X-ray diffraction analysis. Raman spectra confirms the host structure of GST which is confirmed by the two sharp peaks at 126.4 cm(-1) and 144.9 cm(-1) for GST thin films. The hole concentration was found to increase by three orders of magnitude due to Ag doping, as measured by Hall measurements. I-V measurements of the samples show thermal switching at moderate voltage as large current flows through Ag-doped GST. The increase in conductivity was attributed to the crystallization of the films due to heating caused by the large electric current for I-V measurements.