[en] The rewritable bistable memory characteristics have been studied in polymethyl methacrylate (PMMA) and carboxylated multi-walled carbon nanotubes (CNT) composite films. The sandwich structure FTO/PMMA + CNTs/Ag devices were prepared by spin coating and vacuum evaporation process. The device exhibited rewritable bistable resistive switching with switch-on voltage of ~ − 1.5 V, switch-off voltage of ~ 3.4 V, and a high ON/OFF ratio almost of 10⁵. The rewritable behavior of the FTO/PMMA + CNTs/Ag device has been investigated by the endurance test, retention test, and the write-read-erase-reread multiple-cycle tests. The FTO/PMMA + CNTs/Ag device exhibited good retention performance for 2 × 10⁵ s and underwent 10⁴ read pulses. The conduction mechanism in ON state obeys Ohmic conduction; simultaneously, for OFF state, trap-limited space-charge limited conduction was discovered to be the dominant conduction mechanism.

[en] An electron donor–acceptor system composed of a C₆₀ fullerene acceptor and poly(9-vinylcarbazole) (PVK) as the donor has been constructed. This material can respond to both electrical and optical stimuli. Using the C₆₀:PVK blends as the active layer, a solution-processed active layer with a configuration of indium tin oxid (ITO)/C₆₀:PVK/Al is fabricated. Interestingly, when the applied voltages varied from 0 to −0.8 V, the as-fabricated device exhibits both photo-induced resistive state changes and volatile photo-response characteristics in the broadband visible region. The light illumination gives rise to a significant decrease in the device resistance. Furthermore, it is also found that, when the sweep-voltage applied to the device is changed from 0 to ±4 V, this device shows a typical nonvolatile rewritable memory performance in the dark. Upon illumination with different wavelengths of light, both the switching-on voltage and the ON/OFF ratio of the ITO/C₆₀:PVK/Al device are found to be greatly decreased. This work opens up a pathway to the integration of information storage and modulating and demodulating functions in an optoelectronic device. (paper)

[en] To date, the white light lanthanide upconvertion consisting of RGB components usually originated from more than one type of emitter. Alternatively, Pr³⁺ is a fascinating lanthanide ion featuring multiple visible emission bands, including RGB components that in principle enable Pr³⁺ to emit white light. In this paper, we report, for the first time to our knowledge, white light upconversion through dual sensitization routes in Nd/Yb/Pr triply doped NaYF₄ microrods upon 800 nm excitation. It is found that the dual sensitization is more efficient than single sensitization for Pr³⁺ upconversion. In addition, the temperature sensing behaviors of the proposed triply doped microrods are comparatively investigated using different emission bands. This work presents a novel white light emitting material upon 800 nm excitation, and further demonstrates the feasibility of multichannel thermometry using the proposed material.