The impact of ionizing radiation on the retention and endurance of programmable metallization cells (PMC) ReRAM cells is investigated and presented for the first time, with additional work on resistance switching. This study shows that 60Co gamma-ray exposure has a minimal effect on the retention of PMC devices, up to a total ionizing dose (TID) of 2.8 Mrad (Ge30Se70), the maximum TID level tested. The retention of both high resistance states (HRS) and low resistance states (LRS) during exposure was tested. Endurance appears to be slightly reduced with gamma-ray exposure. The endurance was tested to maximum TID of 4.62 Mrad (Ge30Se70). DC response characterizations were also performed on PMC devices after cumulative dose exposures with 50 MeV protons and 100 keV electrons. The data show that PMCs are most sensitive to proton irradiation incident from the backside of the device. For the electron exposures, it is shown that the LRS is mostly unaffected, but the HRS drifts to lower resistance values with an increase in radiation exposure

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In this study we investigated the sorption ability of Ge 20 Se 80 thin films applied as active layers of quartz crystal microbalance (QCM) for NO 2 gas sensing. To identify the chalcogenide system appropriate for gas sensing, we provided data for the packing fraction of a number of chalcogenide systems and discussed their suitability. We performed Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and atom force microscopy (AFM) measurements on the thin films both before and after gas absorption, which showed that the introduced gas molecules interact electrostatically with the chalcogen atoms of the host material and initiate some degree of structural changes in it. The weight change due to NO 2 gas absorption was measured by frequency change of the resonator. The absorbed mass increased monotonically with the thickness of chalcogenide films and the NO 2 gas concentration. At the conditions of our

Light-induced effects in aGe x Se 100-x chalcogenide glasses, i.e., photobleaching (PB), photodarkening (PD), and photoinduced structural transformations, have been investigated as a function of composition across the glass-forming region by an optical two-laser-beam technique, Raman analysis, and first-principles simulations. It was found that there is a critical concentration of Ge x≈30% that corresponds to the crossover from transient PB to the mixture of transient PD and metastable PB. At the microscopic level, this corresponds to the change in the photoexcitation process. At low-Ge concentration (<20%), it is governed by the lone pair (LP) excitation, which diminishes with an increase in Ge content, yielding Ge-Se bond breakage at x≈30%. Further, an increase in Ge concentration (x>30%) favors breakage of the Ge-Ge bonds upon photoexcitation and formation of light-induced 3D nanostructures. The bond conversion process is verified by Raman analysis.

A study on the NO 2 gas sorption ability of amorphous Ge 33 Se 67 coated quartz crystal microbalance (QCM) is presented. The thin films have been characterized before and after sorption/desorption processes of NO 2 by energy-dispersive X-ray spectroscopy (EDS), grazing angle X-ray diffraction (GAXRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and atom force microscopy (AFM) measurements. These studies indicated that physisorption occurs when NO 2 gas molecules are introduced into the chalcogenide film and the thin film composition or structure do not change. The mass loading due to NO 2 gas sorption was calculated by the resonator's frequency shift. At the conditions of our experiment, up to 6.8 ng of the gas was sorbed into 200nm thick Ge 33 Se 67 film at 5000 ppm NO 2 concentration. It has been established that the process of gas molecules sorption is reversible.Keywords: Chalcogenides; Thin films; X-ray photo-emission spectroscopy (XPS); Atomic force microscopy (AFM).