Abstract:
Resistive random access memory (RRAM) is the most promising candidate for next generation nonvolatile memory. In this article, resistive switching in PdO thin film is investigated. The fabricated in-plane devices showed voltage pulse induced multilevel resistive switching (MRS) with as many as five states under ambient conditions with high degrees of retention and endurance. The I-V characteristics of the different memory states are linear and only a small reading voltage (approximate to 10 mV) is necessary. Raman mapping of PdO (B-1g mode, 650 cm(-1)) and temperature-dependent electrical transport measurements provide an insight into possible redox mechanism involving PdO/Pd particles. For the first time, the switching efficiency of a MRS device is uniquely defined in terms of a parameter called "multiplex number (M)," which is the sum of the total number of memory states and the ratio between the number of switching events observed in a device and the total number of possible switching events. The present PdO MRS device exhibits the highest M value compared to the values evaluated from the literature examples. Such high performance MRS in PdO devices makes them potential candidates for RRAM and neuromorphic circuit applications.
