Multilevel Conductance Switching of a Memory Device Induced by Enhanced Intermolecular Charge Transfer

Abstract

The modification of the terminal electron-donating groups induces a critical change in molecular aggregation and the intermolecular charge-transfer effect of the symmetric D-A1-A2-A1-D molecules that correlate with an addressable variation of memory performance from binary to ternary.

Nonvolatile Tri‐State Resistive Memory Behavior of a Stable Pyrene‐Fused N‐Heteroacene with Ten Linearly‐Annulated Rings

“…To further understand the transport behaviors of each resistive switching state, the device tri‐stage I‐V curves at different states were fitted with appropriate charge transport models, as depicted in Figure d–f. According to the model‐fitting, at the HRS the plot of ln( I ) versus V 1/2 could be well‐fitted to a straight line, whereas at the IRS the plot of I versus V 2 is linear, and at the LRS that of ln( I V −1 ) versus V 1/2 is linear . Thus, the 1 ‐based ORM device showed different transport behaviors at different resistive states; charge‐injection‐dominated thermionic emission at the HRS, trap‐limited space‐charge‐limited current (SCLC) control at the IRS, and charge‐transport‐dominated Poole–Frenkel (PF) emission at the LRS .…”

“…The statistic result reveals that, the yield of ternary devices, as defined by the proportion of achieving output TROS behavior, is about 78 % (see from column‐chart plot in Figure d, left). Recent studies of TROS indicate that the ternary memory yields of some organic‐based materials are usually insufficient (≈50 %) . Regarding this defect, 1 could be considered as an excellent ternary NVM media with satisfactory reproducibility.…”

“…Organic memory is aparticularly interesting field, which holdsgreat potentiali nt he next-generation of information-storage technology. [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] As an ewly-emerging research topic, ORMh as raised growingi nterestd ue to its charming advantages including low cost, high flexibility,a nd possibility to substitute conventional inorganic Si-based memories. [24][25][26][27][28][29][30][31] Although somer eported ORM materials have been demonstrated to achieveu ltra-high density data-storage applicationst hrough multistate read-out signals (MROS), [33][34][35][36][37][38] they often suffer from the inferiorr epeatability of the resistive behaviors and inconsistent endurable stability, [33][34][35] whichl ags far behind the key requiremento ff uture data-driven computation.…”

“…Recent studies of TROS indicate that the ternary memory yields of some organic-basedm aterials are usually insufficient ( % 50 %). [34,45] Regarding this defect, 1 couldb ec onsidered as an excellent ternary NVM media with satisfactory reproducibility.M oreover,w ei llustrated the statistic distribution of V SET sb y an error bar (Figure 3d,r ight). As shown in Figure 3d,t he first SET voltage (V SET 1) and second SET voltage (V SET 2) are well-separated.…”

“…According to the model-fitting, at the HRS the plot of ln(I)v ersus V 1/2 couldb ew ell-fitted to as traight line, whereas at the IRS the plot of I versus V 2 is linear,a nd at the LRS that of ln(IV À1 )v ersus V 1/2 is linear. [34] Thus, the 1-based ORM devices howed different transport behaviorsa td ifferent resistive states;c harge-injection-dominated thermionic emission at the HRS, trap-limited space-charge-limited current (SCLC) control at the IRS, and charge-transport-do-minatedP oole-Frenkel (PF) emission at the LRS. [38] Changes of the charge transport models at different states also support the field-induced tri-stability of 1.S ystematic DFT calculations and model-fitting allow for touching the underlying principle behind the switching performance, which is important to gain ac omprehensive understanding of the 1-based device.…”