Memristive, memcapacitive and meminductive behavior of single and co-doped cadmium selenide nanocomposites under different doping environment

Abstract

Undoped and Mn/Cu/(Mn+Cu) doped CdSe colloidal quantum dots embedded in Starch matrix have been synthesized by adopting single-step chemical bath deposition method. X-ray diffraction (XRD) results show cubic zinc blende structures in both doped and undoped samples. The estimated particle sizes from the XRD are found to be in the range (6.9–10.3) nm. The HRTEM images exhibit irregular shaped nanoparticles with size in the range (6–10.2) nm. Thus, the particle sizes estimated from XRD results roughly agree with those from HRTEM measurements. The UV–Vis absorption spectra for both doped and undoped samples show blue shift, suggesting quantum confinement. All the undoped and doped samples show PL emission in the range 510–653 nm. PL intensity is found to increase due to doping. Two terminal electrochemical devices are fabricated with the as-prepared doped and undoped samples as the active layer with ITO coated glass slide and aluminum (Al) as electrodes. I–V characteristics of the as-fabricated devices exhibit pinched hysteresis loops having memristive, memcapacitive and meminductive nature. A new parameter is conceptualized which is found to be sensitive to doping material as well as doping concentration. Schottky emission mechanism is found to be dominant in both low resistance state and high resistance state. ON/OFF switching features favour Coulomb Blockade phenomenon.