Dopant dependent electrical switching characteristics of a CdSe- Poly(vinyl-pyrrolidone) nanocomposite

This work highlights the effect of Ag doping on the electrical switching mechanism of CdSe-PVP nanocomposite devices. Ag:CdSe-PVP nanocomposites were synthesized through chemical route at three different Ag doping concentrations (0.1%, 0.2% and 0.3%). XRD spectra of polymer nanocomposites revealed the zinc blende structure with dominating (111) crystal plane. Electrically induced switching between low and high conductivity states of two terminal memory devices was demonstrated through I-V, C-V and Write Read Erase Read sequences. Hysteresis behaviour in I-V and C-V measurements is due to the slow relaxation dynamics of the accumulated space charge carriers in Ag:CdSe-PVP nanocomposite. With 0.1% Ag doping, the device I-ON/I-OFF ratio increases by a factor of 10 as compared to pure CdSe-PVP nanocomposite. With 0.2% and 0.3% Ag doping, the device I-ON/I-OFF ratio decreases due to the increased particle-particle interaction as compared to particle-polymer interaction. Endurance characteristics showed the good stability and reliability of 0.1% Ag:CdSe-PVP NC with device I-ON/I-OFF ratio similar to 4 x 10(2). The obtained results open up the possibility of improving the memory performance of polymer nanocomposites by adjusting the metal ion doping concentration through simple fabrication processes.