Memory effect of nonvolatile bistable devices based on CdSe∕ZnS nanoparticles sandwiched between C60 layers

Abstract

Current-voltage and conductance-voltage (G-V) measurements on three-layer Al∕C60∕CdSe nanoparticles∕C60∕indium tin oxide (ITO) structures fabricated by using a spin-coating method showed a nonvolatile electrical bistable behavior. Capacitance-voltage (C-V) measurements on Al∕C60∕CdSe nanoparticles∕C60∕ITO structures showed a clockwise hysteresis with a flatband voltage shift due to the existence of the CdSe nanoparticles, indicative of memory effects in the devices. Current-time measurements showed that the devices exhibited excellent memory retention ability at ambient conditions. Possible operating mechanisms for the memory effects in the Al∕C60∕CdSe nanoparticles∕C60∕ITO devices are described on the basis of the G-V and the C-V results.

Electrical memory devices based on inorganic/organic nanocomposites

“…Thus, the multilayer structure, where inorganic nanoparticles are sandwiched between organic layers, has been employed in order to obtain memories with high stability and reproducibility. 37 The main challenge to obtain such a structure is the dissolving of the underlying polymer layer caused by the solvent used to form the upper polymer layer. Thus, the key point in realizing a multilayer structure is the availability of an appropriate polymer material.…”

Relationship between the particle size of quantum dots and bistability of the quantum dot embedded organic memory devices

“…The bistability of the device I is closely related with the charge trapping effect of the QD nanoparticles. As reported in previous work by Kim and co-workers, the CdSe/ZnS QD nanoparticles trap and detrap charges depending on the applied vias [10]. The OBDs are at low conductance state before applying a positive voltage and then the current increases monotonously according to the applied voltage.…”

“…MoO 3 was inserted between small molecule organic materials and stable bistability was observed for the MoO 3 based OBDs. In addition to the metal and inorganic nanoparticles, a CdSe/ ZnS nanoparticle was reported to improve the bistability of OBDs [10]. The CdSe/ZnS nanoparticles were inserted as an interlayer between C60 layers and a high on/off ratio was obtained.…”

Enzyme Immobilization on Layered and Nanostructured Materials

“…Passing the transmission of the macro to nanoscale the properties of many nanoparticles change upon dimensional confi nement including magnetism [166] , catalysis [167] , and mechanical properties [168] . Importantly, the unique properties of nanoscale solids can be used for a variety of applications, including information storage [169] , medical and biological imaging [170] , and catalysis for energy [171] (Figure 2.3 ). Nanoparticles provide functional surface area to increase enzyme loading and a biocompatible microenvironment helping enzyme to retain its catalytic properties, while the diffusion limitations are minimized due to the nano -scale dimensions.…”