Conduction and Resistive Switching in Dropcast CdTe/CdSe Core-Shell Quantum Dots Embedded Chitosan Composite

We report on conduction and resistive switching in devices consisting of chitosan dispersed with CdTe/CdSe core-shell quantum dots (QDs) active layers sandwiched between silver (Ag) and indium doped tin oxide (ITO) electrodes. Active layers consisting of 0.96wt%, 0.48wt%, 0.32wt% and 0.24wt% QDs to chitosan were deposited on the ITO surface using the cost-free drop cast method. The electrical study performed on all devices revealed ‘O-type’ memory behaviour with OFF-state current conduction mechanism attributed to hopping mechanism. On the other hand, the ON-state current in each device followed a unique mechanism, such that Ohmic behaviour was observed for the device with 0.96wt%, while linear then hopping, space-charge limited, and lastly, hopping conductions mechanisms were attributed to devices with 0.48wt%, 0.32wt% and 0.24wt%, respectively. Our results show that these devices’ memory behaviour and conduction can be exploited by controlling the amount of CdTe/CdSe in the chitosan medium.