PbS1−xSex-Quantum-Dot@MWCNT/P3HT Nanocomposites with Tunable Photoelectric Conversion Performance

The photoelectric performance of quantum dots (QDs)-based nanocomposites is closely related to the optical properties of QDs, which play a critical role in the optical absorption and separation/transfer of charge carriers. Herein, we report a nanocomposite composed of light absorber PbS1−xSex quantum dots (QDs), electron-conducting multiwalled carbon nanotubes (MWCNTs) and hole-conducting poly-3-hexylthiophene (P3HT) with tunable photoelectric conversion performance. In addition to using the quantization effect, we proposed solid-solution PbS1−xSex QDs (x = 0, 0.25, 0.5, 0.75, 1) for band gap engineering. In particular, we successfully synthesized relatively small (~5.3 nm) and uniform QDs via the hot-injection method by using PbCl2, S/Se powder and environmentally friendly oleylamine (OLA) as the precursors and/or solvent. By increasing the content of Se, the band gap of PbS1−xSex QDs decreased along with the decrease in the conduction band and valence band edges. The suitable energy level alignment enabled the efficient transfer of photoinduced charge carriers, and hence a much higher photoelectric conversion performance of the PbS1−xSex-QD@MWCNT/P3HT nanocomposites than the individual QDs, P3HT, and binary PbS1−xSex-QD@MWCNT, as well as the best performance, was achieved over PbS0.75Se0.25-QD@MWCNT/P3HT.

Event-triggered guaranteed cost control of time-varying delayed fuzzy systems with limited communication

Modern network applications place higher demands on its controller, especially for those with time-varying delays and limited communication capacity. For such cases, the fuzzy system has already become an advanced and powerful tool to deal with the control problem in consideration of a guaranteed cost performance. In this paper, we introduce the event-triggered mechanism with quantization effect to the controller, which proves to be more effective in terms of the information transmission. We adopt the classical Lyapunov approach to find the sufficient conditions for the controller and we illustrate the effectiveness of the controller with a numerical simulation.

Квантование проводимости в мемристивных структурах на основе поли-п-ксилилена

The paper presents the results of a study at room temperature of the quantization effect of the conductivity of memristive structures based on the organic material poly-p-xylylene with resistive switching. Measurement methods are shown and a comparative analysis of the manifestation of the effect when switching structures to a high-resistance and low-resistance state is carried out. The possibility of setting stable quantum states of conductivity in memristive structures based on poly-p-xylylene is demonstrated. It is shown that some of these states have short-term, and some long-term stability. The results obtained open up new possibilities for using the quantization effect of conductivity in the implementation of neuromorphic systems.