In this study, a memristor with the simple structure Ag/poly(3,4-ethylenedioxythiophene):poly (styrenesulphonate) (PEDOT:PSS)/Ta was fabricated. Essential synaptic plasticity and learning behaviours were emulated using this memristor, including short-term plasticity, long-term plasticity, spike-timing-dependent plasticity and spike-rate-dependent plasticity. Important time constants were extracted from these synaptic modifications, which are associated with brain learning and memory functions. It was clearly demonstrated that the movement of the Ag interface upon the initiation of a redox reaction accounts for the resistive switching mechanism of our memristor. The conducting path in the polymer layer and the elastic effect of the polymer matrix were suggested to be considered in the memory and learning processes. Moreover, the energy band diagram of our memristor was drawn after the cross-sectional transmission electron microscopy images were analysed. It was found that a natural p–n junction in the PEDOT:PSS/Ta compound was formed. This resulted in rectifying, high resistance and low power consumption. Our device structure may be considered a feasible prototype for integrating memristors into a large-scale neuromorphic circuit.

The electrocaloric effect (ECE) of BaTiO3 multilayer thick film was investigated by direct calorimetric measurement. The ECE increases monotonically with the enhancement of applied field. The maximum ECE occurs above Tc and shifts to higher temperature with increasing applied field. Under an ultrahigh field of 800 kV/cm, it exhibits a giant ECE of ΔT = 7.1 K and ΔS = 10.1 J/kg · K at 80 °C. The ECE heat follows a general power-law relation with the varying rate of applied field within a certain range. A high cooling power (∼50 W/kg) is achieved based on the net-cooling resulting from the different varying rates of rising and falling fields.

This paper presents a systematic exploration of modifying the electrocaloric effect (ECE) in BaTiO ₃ ceramics by rare-earth substitution (Ba _0.94 R _0.04 TiO ₃ , R = La, Ce, Nd, Sm, Eu, Gd, Dy, Er).

Polarization variation in a thermal cycle and in situ HT d₃₃ revealed real depolarization temperature and distinct d₃₃ recovery.

Pentacene thin film transistors (TFTs) were fabricated by the organic molecular beam deposition method. The TFTs were characterized in order to study the effect of thermal annealing on the morphology and carrier mobility of the transistors. For all the TFT samples the mobility exhibited an Arrhenius relationship with temperature, indicating a thermally activated transport that could be explained by the carrier trap and thermal release transport mechanism. Therefore, in order to investigate the annealing effect, we tested the data for a significant period of time after annealing until the temperature recovered to room temperature, so that the thermal activation effect was screened and possible effects of thermal expansion and stress were also ruled out. As a result, we found that only with a temperature below a critical temperature of approximately $45°\mathrm{C}$ could annealing improve the mobility, while annealing with $T>50°\mathrm{C}$ would decrease the mobility compared to the value before annealing. Atomic force microscopy observation and x-ray diffraction (XRD) data indicated that annealing caused decreased grain size and decreased XRD peak intensity for all samples. Increasing the annealing temperature to $70°\mathrm{C}$ caused obvious desorption because of the low van der Waals intermolecular forces in the organic film. The mobility deterioration after high temperature annealing may be ascribed to the deteriorated microstructure, while the improved mobility may result from the increased crystallinity in the bottom several layers near the substrate film interface. The results also suggested that the influence of possible structure evolution should be distinguished when investigating temperature dependent transport properties.