All inorganic spin-coated nanoparticle memory device

Summary form only given. Two terminal floating gate capacitive memory structures with novel materials and fabrication strategies continue to attract tremendous interest since they form the backbone of conventional nonvolatile flash memory technology. Some of these approaches that involve high temperature deposition or ultra-high vacuum systems are not suitable for low-cost large area electronics. Spin-coated polymer memory devices with low temperature processing have been demonstrated as an alternative. However, most of them are resistively switched memories which are incompatible with standard flash technology. Moreover, polymer devices are environmentally unstable and quickly degrade at elevated temperatures and ambient air operating conditions. Here we demonstrate a two-terminal all inorganic spin coated capacitive memory device using Aluminum Oxide Phosphate (ALPO) as the dielectric and Cadmium Telluride Nanoparticles (CdTe-NP) for charge storage. These structures can be used to realize transistors whose threshold voltage can be switched depending on the charge stored in the nanoparticles. In two-terminal capacitive devices, an experimental challenge is to measure the threshold voltage (or equivalently the flatband voltage V_FB) without disturbing the memory state. Conventional LCR meters with slow DC sweeps generate CV curves (LCRCV) with hysteresis, showing that the charge storage, and hence memory state, is altered during the measurement itself. In order to decouple the memory programming (“writing”) with the flatband voltage measurement (“reading”), we have realized a simple high speed CV (HSCV) pulse circuit that completes the measurement in less than 10 μs, faster than the time required to change the charge state.