Colloidal MoS2 quantum dots for high-performance low power resistive memory devices with excellent temperature stability

Abstract

Conventional memory technologies are facing enormous problems with downscaling, and are hence unable to fulfill the requirement of big data storage generated by a huge explosion of digital information. A resistive random access memory device (RRAM) is one of the most emerging technologies for next-generation computing data storage owing to its high-density stacking, ultrafast switching speed, high non-volatility, multilevel data storage, low power consumption, and simple device structure. In this work, colloidal MoS2 quantum dots (QDs) embedded in an insulating matrix of poly-(4vinylpyridine) (PVP) were used as an active layer to fabricate a RRAM device. The MoS2 QDs-PVP based RRAM device reveals an excellent nonvolatile resistive switching (RS) behavior with a maximum current on-off ratio (ION/IOFF) of 105. High endurance, long retention time, and successive “write-read-erase-read” cycles indicate high-performance RRAM characteristics. The ultimate power consumption by this RRAM device is considerably low for energy saving. In addition, the MoS2 QDs-PVP based device shows RS behavior even at 130 °C. High ION/IOFF, low operating power, high endurance, long retention time, and excellent stability with temperatures reveal that the MoS2 QDs-PVP based device can be a promising candidate for high-performance low power RRAM devices that can be operated at relatively higher temperatures.

MoS2 Quantum Dot-Optimized Conductive Channels for a Conjugated Polymer-Based Synaptic Memristor

“…The XRD pattern of MoS 2 QDs was noisy due to the small size of MoS 2 QDs, but the (004) and (105) crystal planes could be identified, which also indicates that MoS 2 QDs retained the hexagonal phase. 36,41 The XPS survey spectrum of MoS 2 QDs in Figure S3a illustrates a Mo 3d peak near 229 eV and an S 2p peak near 162 eV, which are consistent with the structure of the MoS 2 QDs. There are hexagonal phases (2H phase) and tetragonal phases (1T phase) in the MoS 2 QDs.…”

“…In Figure h, the peaks at 229.05 and 232.21 eV correspond to Mo 3d 5/2 and Mo 3d 3/2 states in 2H-MoS 2 , respectively. , We also observed a peak at 223.40 eV, which was attributed to the S 2s state in the MoS 2 QDs. In Figure i, the peaks at binding energies of 162.38 and 163.39 eV were assigned to the S 2p 3/2 and S 2p 1/2 states in 2H-MoS 2 , respectively. , …”

“…The HOMO/LUMO energy levels of MoS 2 QDs were calculated to be −6.27 and −3.77 eV, respectively. The optical band gap E g = 2.5 eV was measured from the Tauc plot of the UV–vis spectral data (Figure b) . The analysis of the combined energy levels of PM6 and MoS 2 QDs reveals that PM6 serves as an electron donor, while MoS 2 QDs act as electron acceptors.…”

“…In Figure 1i, the peaks at binding energies of 162.38 and 163.39 eV were assigned to the S 2p 3/2 and S 2p 1/2 states in 2H-MoS 2 , respectively. 41,42 Comparing the FTIR spectra of MoS 2 QDs and MoS 2 crystal, the stretching vibration absorption peak (ν = 467 cm −1 ) ascribed to the Mo−S bond in MoS 2 QDs disappeared due to the reduction of MoS 2 layers during MoS 2 QDs size reduction, 35 which was caused by decreased interactions between layers, providing strong evidence for the successful preparation of MoS 2 QDs (Figure S3b). Photoluminescence spectroscopy was conducted on the prepared MoS 2 QDs.…”

Non-volatile memristor-based artificial synaptic behavior of redox-active organic composites

“…Thin film-based resistive memory has been studied using different materials, such as inorganic thin films, 9,10 nanoparticles, 11,12 quantum dots, 13 organic small molecules, 14,15 long-chain polymers, 16 organic-inorganic hybrid materials, 16 quantum dots and polymer composites. [17][18][19] Small organic molecule-based electronic devices are the point of interest because of their small size, high stability, low power consumption, excellent flexibility, etc. 20,21 The cheap, biocompatible, and easy fabrication of memristors make the small molecules capable of high-density memory storage application.…”