Electrical and switching behavior of quaternary defect chalcopyrite CdInGaSe4 thin films

CdInGaSe4 thin films were prepared by thermal evaporation technique. The amorphous nature of the thin films was confirmed by X-ray analysis. The elemental composition of thin film samples was determined by energy-dispersive X-ray spectrometry revealing the stoichiometric compositions of the material. The temperature and thickness dependences of DC electrical conductivity σ DC were studied, in the temperature and thickness ranges (303–423 K) and (71–198 nm), respectively. The results indicate that the conduction occurs through a thermally activated process having two conduction levels. The switching phenomenon was studied; the obtained I–V curves are typical for memory switch. The value of V th increases with film thicknesses, while it decreases exponentially with increasing temperature. The value of threshold field E th calculated and found to decrease with increasing temperature. The ratio between the threshold activation energy Δɛ th and the electrical activation energy ΔE σ2 was calculated and found to be (\(\frac{{\Delta \varepsilon_{\text{th}} }}{{\Delta E_{\sigma 2} }}\) ≈ 0.93 eV), which can be explained according to thermal model. Values of ΔT breakdown were also calculated and found to increase with temperature.