Effect of CuPc layer insertion on the memory performance of CdS nanocomposite diodes

• CdS nanocomposite as an active layer investigated for memory device application.
• Effect of copper phthalocyanine layer insertion on the memory performance studied.
• Bipolar switching behaviour with high ON/OFF ratio ̃1.4 × 104.
• Series resistance and interface states dominate the electrical properties of the device.

In the present work, semiconductor diodes with CdS nanocomposite as an active layer have been fabricated and investigated for memory device applications. The effect of copper phthalocyanine (CuPc) layer insertion between the bottom electrode and CdS nanocomposite has been studied. I–V characteristics show electrical hysteresis behaviour vital for memory storage application. The as-fabricated devices exhibit bipolar switching behaviour with OFF to ON state transition at positive bias and vice versa. Device with CuPc layer exhibits ION/IOFF ratio ̃ 1.4 × 104. Possible conduction mechanism has been described on the basis of theoretical current conduction models. The frequency dispersion capacitance, series resistance and conductance of the devices have been studied and discussed. At low frequency, the series resistance and the interface states dominate the electrical properties of the device. The results indicate that the multilayered devices open up the possibility of new generation non-volatile memory devices with low cost, high density and stability.