Thermoelectric Seebeck effect in oxide-based resistive switching memory

Abstract

Reversible resistive switching induced by an electric field in oxide-based resistive switching memory shows a promising application in future information storage and processing. It is believed that there are some local conductive filaments formed and ruptured in the resistive switching process. However, as a fundamental question, how electron transports in the formed conductive filament is still under debate due to the difficulty to directly characterize its physical and electrical properties. Here we investigate the intrinsic electronic transport mechanism in such conductive filament by measuring thermoelectric Seebeck effects. We show that the small-polaron hopping model can well describe the electronic transport process for all resistance states, although the corresponding temperature-dependent resistance behaviours are contrary. Moreover, at low resistance states, we observe a clear semiconductor–metal transition around 150 K. These results provide insight in understanding resistive switching process and establish a basic framework for modelling resistive switching behaviour.

Set statistics in conductive bridge random access memory device with Cu/HfO2/Pt structure

“…[1][2][3] The resistive switching (RS) characteristics and mechanisms of RRAM have received significant attention recently. [4][5][6][7][8] It has been widely accepted that the partial connection and rupture of conducting filaments (CFs) in metal oxides are responsible for set and reset switching. However, the intrinsic stochastic nature of the reconnection of ruptured CFs results in the variation of the switching parameters, which has been one of the primary bottlenecks for the commercial application of RRAM.…”

Polaron effect and energetic disorder dependence of Seebeck coefficient in organic transistors

“…The Seebeck coefficient, which is determined by the sign and concentration of the dominant charge carrier, can provide direct insights in the energetics of dominant charge transport processes and determine the average transport energy of carriers [8,9]. More importantly, the Seebeck voltage does not depend on the interfacial contact [10], hence the Seebeck coefficient can really uncover the intrinsic charge carrier transport. During the last decades, the Seebeck coefficient has been widely observed and experimentally investigated.…”

Formation and dynamics of small polarons on the rutile TiO2 (110) surface

“…[1][2][3] The presence of such a localized charge affects the physical and chemical properties of the hosting material, with a local alteration of the bond lengths, a change of the formal valence at the specific polaronic site, and the emergence of a characteristic peak localized in the gap region. [4][5][6][7] Small polarons play a decisive role in electron transport, 8,9 optical absorption, and chemical reactivity, and have crucial implications in other diverse phenomena including high-T c superconductivity, 10 colossal magnetoresistance, 11,12 thermoelectricity, 13 photoemission, 14 and photochemistry. 15 Here we focus on the (110) surface of rutile TiO 2 , TiO 2 (110), a highly studied oxide surface 16 for which the presence of small polarons was predicted by different computational approaches [17][18][19][20] and confirmed by several experiments.…”