Electrical Bistabilities and Conduction Mechanisms of Nonvolatile Memories Based on a Polymethylsilsesquioxane Insulating Layer Containing CdSe/ZnS Quantum Dots

Abstract

Nonvolatile memory (NVM) devices based on a metal-insulator-metal structure consisting of CdSe/ZnS quantum dots embedded in polymethylsilsesquioxane dielectric layers were fabricated. The current-voltage (I-V) curves showed a bistable current behavior and the presence of hysteresis. The current-time (I-t) curves showed that the fabricated NVM memory devices were stable up to 1 x 10(4) s with a distinct ON/OFF ratio of 10(4) and were reprogrammable when the endurance test was performed. The extrapolation of the I-t curve to 10(5) s with corresponding current ON/OFF ratio 1 x 10(5) indicated a long performance stability of the NVM devices. Schottky emission, Poole-Frenkel emission, trapped-charge limited-current and Child-Langmuir law were proposed as the dominant conduction mechanisms for the fabricated NVM devices based on the obtained I-V characteristics.