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The study about the effect of the stacking mode on the photo/electrical performance of crystalline organic/inorganic hybrids will be beneficial for the design of new photo/electrically active materials. In this work, D–π–A stilbazolium-type chromophores bearing novel ortho-N-alkyl substituents were synthesized and incorporated with iodoargentates to generate three crystalline stilbazolium/iodoargentate hybrids, i.e., [(CMAMP)(Ag2I3)]n (1), [(HMAMP)(Ag2I3)]n (2), and [(HMAHP)2(Ag5I7)]n (3). When the substitutes on the amine group range from –C2H5CN (for CMAMP+) to –C2H5OH (for HMAMP+), the same (Ag2I3)nn− anions will be produced, and the π⋯π stacking interactions among stilbazoliums will be observed from absence to presence (weak head-to-head H-aggregation). Furthermore, when the substituent on the ortho-N of pyridine was also set as –C2H5OH (for HMAHP+), more electron-rich (Ag5I7)n2n− anion can be generated, and strong head-to-tail H-aggregation among HMAHP+ cations will happen. The enhanced aggregation strengthening in 3 can lead to its larger blue-shift photoluminescence, higher photocurrent, and better resistive switching performance (much higher ON/OFF ratio of 4.51 × 102). Their binary resistive switching mechanism can be explained as the SCLC model, and the better photo/electrical performances of 3 stem from its stronger head-to-tail H-aggregations, more negatively charged (Ag5I7)n2n− anion, and stronger (Ag5I7)n2n−–HMAHP+ interaction. The highly delocalized π antibonding orbitals between the empty p-orbitals of ethylene in its LUMO of (HMAHP)22+ dimer of 3 also support this conclusion. The good structure–property correlation based on accurate structural information in these stilbazolium/iodoargentate hybrids will be beneficial for the design of next-generation memory devices. [ABSTRACT FROM AUTHOR]

The development of new‐type memristors with special performance is of great interest. Herein, an inorganic‐organic hybrid crystalline polyoxometalate (POM) with usual dynamic structures is reported and used as active material for fabricating memristor with unique temperature‐regulated resistive switching behaviors. The hybrid POM not only exhibits tunable thermochromic properties, but also thermal‐induced reversible aggregation and disaggregation reactions, leading to reversible structural transformations in SCSC fashion. Further, the memory device using the hybrid POM as active layer exhibits uncommon performance, which can keep resistive switching silent in the low temperature range of 30–150 °C, but show nonvolatile memory behavior in the high temperature range of 150–270 °C. Particularly, the silent and working states at three special temperatures (30, 150 and 270 °C) can be monitored by chromism. The correlation between structure and resistive switching property of the material has been discussed. The work demonstrates that crystalline inorganic‐organic hybrid POMs are promising materials for making memristors with superior performance. [ABSTRACT FROM AUTHOR]

The development of new‐type memristors with special performance is of great interest. Herein, an inorganic‐organic hybrid crystalline polyoxometalate (POM) with usual dynamic structures is reported and used as active material for fabricating memristor with unique temperature‐regulated resistive switching behaviors. The hybrid POM not only exhibits tunable thermochromic properties, but also thermal‐induced reversible aggregation and disaggregation reactions, leading to reversible structural transformations in SCSC fashion. Further, the memory device using the hybrid POM as active layer exhibits uncommon performance, which can keep resistive switching silent in the low temperature range of 30–150 °C, but show nonvolatile memory behavior in the high temperature range of 150–270 °C. Particularly, the silent and working states at three special temperatures (30, 150 and 270 °C) can be monitored by chromism. The correlation between structure and resistive switching property of the material has been discussed. The work demonstrates that crystalline inorganic‐organic hybrid POMs are promising materials for making memristors with superior performance. [ABSTRACT FROM AUTHOR]

The searching for green memristor with good environmental robustness will be significant for next generation biodegradable devices. In this work, bio-compatible and non-toxic polydopamine (PDA) was prepared by self-polymerization of dopamine in simple aqueous solution, which was protonated by different acid concentrations (3–12 M HCl) and further fabricated as memory devices with structures of FTO/PDA/Ag. The ON/OFF ratio are enhanced gradually from 2.80 × 102 (PDA-3 M), 8.39 × 102 (PDA-6 M), 5.18 × 103 (PDA-9 M) to 2.41 × 104 (PDA-12 M). The lower conjugated degree, the closer lattice packing and the less radicals after acid treatment are the reasons for the enhanced bipolar resistive switching performances of protonated PDA-based memristor. The resistive switching mechanism is the conductive filament with three processes of Ohm, space charge limited conduction (SCLC) and trap-filled limited (TFL). In addition, the FTO/PDA-12 M/Ag exhibit good environmental robustness, including thermal (100 °C) and ionizing irradiation (UV exposure for 96 h). In all, the facial protonation treatment and the simple sandwich device structures together with good environmental robustness endow its promising applications in as green, stable and biodegradable next generation electron devices. The enhanced bipolar resistive switching performance and good environmental robustness can be achieved in protonated polydopamine based memristor, which is assigned to the lower conjugated degree, the closer lattice packing and the less radicals after acid treatment. [Display omitted] • Bio-compatible polydopamine was protonated by different acid concentrations and further fabricated as memory devices. • The reasons for the enhanced bipolar resistive switching performances of protonated PDA-based memristor was discussed. • The FTO/PDA-12 M/Ag exhibits good thermal (100 °C) and ionizing irradiation (UV exposure for 96 h) robustness. [ABSTRACT FROM AUTHOR]

• Memory devices fabricated with protonated g-C 3 N 4 can exhibit enhanced memory performances, in which acid concentration is crucial. • g-C3N4 treated with 8 M HCl presents the best resistive switching performance, which might be relative to its texture without violent tortuosity. • The protonated g-C 3 N 4 -based memory devices present good environmental robustness, including temperature and ionizing irradiation. • The high tolerant temperature (454 °C) can also be enhanced by doping BN for heat dissipation. Memory devices with simple sandwich structures using the g-C 3 N 4 treated by different concentration acids as active layers have been fabricated, which exhibit enhanced non-volatile bipolar switching performances and good environmental robustness. [Display omitted] The searching for new memory that can work under harsh conditions will be significant for their application in some important fields such as geothermal, oil and aerospace industries. In this work, memory devices with simple sandwich structures using the g-C 3 N 4 treated by different concentration acids as active layers have been fabricated, which exhibit non-volatile behaviors and bipolar switching characteristics. Protonation treatment can enhance the memory performance efficiently compared with un-protonized device. Among them, the device containing g-C 3 N 4 treated with 8 M HCl presents the best resistive switching performance with ON/OFF ratio of 104 and good retention capability, which might be relative to its texture without violent tortuosity. In addition, the protonated g-C 3 N 4 -based memory devices exhibit good environmental robustness, including temperature and ionizing irradiation. Specially, its high tolerant temperature (454 °C) can also be assisted by doping BN for heat dissipation. Their good thermal/irradiating stabilities are assigned to the strong bond energy of C N double bonds localized π-conjugated tri-s-triazine rings. In all, the facial protonation treatment without any functionalization or supporting, the simple sandwich device structure and good environmental robustness endow their promising applications in aerospace and outdoor environment. [ABSTRACT FROM AUTHOR]