Immobilization of enzyme and antibody on ALD-HfO2-EIS structure by NH3 plasma treatment

Thin hafnium oxide layers deposited by an atomic layer deposition system were investigated as the sensing membrane of the electrolyte-insulator-semiconductor structure. Moreover, a post-remote NH3 plasma treatment was proposed to replace the complicated silanization procedure for enzyme immobilization. Compared to conventional methods using chemical procedures, remote NH3 plasma treatment reduces the processing steps and time. The results exhibited that urea and antigen can be successfully detected, which indicated that the immobilization process is correct

Gadolinium oxide nanocrystal nonvolatile memory with HfO2/Al2O3 nanostructure tunneling layers

In this study, Gd2O3 nanocrystal (Gd2O3-NC) memories with nanostructure tunneling layers are fabricated to examine their performance. A higher programming speed for Gd2O3-NC memories with nanostructure tunneling layers is obtained when compared with that of memories using a single tunneling layer. A longer data retention (< 15% charge loss after 104 s) is also observed. This is due to the increased physical thickness of the nanostructure tunneling layer. The activation energy of charge loss at different temperatures is estimated. The higher activation energy value (0.13 to 0.17 eV) observed at the initial charge loss stage is attributed to the thermionic emission mechanism, while the lower one (0.07 to 0.08 eV) observed at the later charge loss stage is attributed to the direct tunneling mechanism. Gd2O3-NC memories with nanostructure tunneling layers can be operated without degradation over several operation cycles. Such NC structures could potentially be used in future nonvolatile memory applications

Data Retention Characterization of Gate-Injected Gold-Nanoparticle Non-Volatile Memory with Low-Damage CF4-Plasma-Treated Blocking Oxide Layer

Gold-nanoparticle (Au-NP) non-volatile memories (NVMs) with low-damage CF4 plasma treatment on the blocking oxide (BO) layer have been investigated to present the gate injection of the holes. These holes, injected from the Al gate with the positive gate bias, were explained by the bandgap engineering of the gradually-fluorinated BO layer and the effective work function modulation of the Al gate. The Si–F complex in the BO layer was analyzed by X-ray photoelectron spectroscopy (XPS), while the depth of fluorine incorporation was verified using a secondary ion mass spectrometer (SIMS). In addition, the valence band modification of the fluorinated BO layer was examined by ultraviolet photoelectron spectroscopy (UPS) to support the bandgap engineering. The reactive power of the CF4 plasma treatment on the BO layer was modified to increase the electric field of the BO layer and raise the effective work function of the Al gate, leading to the hole-injection from the gate. The injected holes are trapped at the interface between the gold-nanoparticles (Au-NPs) and the tunneling oxide (TO) layer, resulting in superior data retention properties such as an extremely low charge loss of 5.7% at 104 s and a nearly negligible increase in charge loss at 85 °C of the CF4-plasma-treated Au-NP NVMs, which can be applied in highly reliable consumer electronics

Nanoscale Multidimensional Pd/TiO2/g-C3N4 Catalyst for Efficient Solar-Driven Photocatalytic Hydrogen Production

Solar-to-fuel conversion is an innovative concept for green energy, attracting many researchers to explore them. Solar-driven photocatalysts have become an essential solution to provide valuable chemicals like hydrogen, hydrocarbon, and ammonia. For sustainable stability under solar irradiation, titanium dioxide is regarded as an acceptable candidate, further showing excellent photocatalytic activity. Incorporating the photo-sensitizers, including noble metal nanoparticles and polymeric carbon-based material, can improve its photoresponse and facilitate the electron transfer and collection. In this study, we synthesized the graphitic carbon nitride (g-C3N4) nanosheet incorporated with high crystalline TiO2 nanofibers (NF) as 1D/2D heterostructure catalyst for photocatalytic water splitting. The microstructure, optical absorption, crystal structure, charge carrier dynamics, and specific surface area were characterized systematically. The low bandgap of 2D g-C3N4 nanosheets (NS) as a sensitizer improves the specific surface area and photo-response in the visible region as the incorporated amount increases. Because of the band structure difference between TiO2 and g-C3N4, constructing the heterojunction formation, the superior separation of electron-hole is observed. The detection of reactive oxygen species and photo-assisted Kelvin probe microscopy are conducted to investigates the possible charge migration. The highest photocatalytic hydrogen production rate of Pd/TiO2/g-C3N4 achieves 11.62 mmol&middot;h&minus;1&middot;g&minus;1 under xenon lamp irradiation

Nb2O5 and Ti-Doped Nb2O5 Charge Trapping Nano-Layers Applied in Flash Memory

High-k material charge trapping nano-layers in flash memory applications have faster program/erase speeds and better data retention because of larger conduction band offsets and higher dielectric constants. In addition, Ti-doped high-k materials can improve memory device performance, such as leakage current reduction, k-value enhancement, and breakdown voltage increase. In this study, the structural and electrical properties of different annealing temperatures on the Nb2O5 and Ti-doped Nb2O5(TiNb2O7) materials used as charge-trapping nano-layers in metal-oxide-high k-oxide-semiconductor (MOHOS)-type memory were investigated using X-ray diffraction (XRD) and atomic force microscopy (AFM). Analysis of the C-V hysteresis curve shows that the flat-band shift (∆VFB) window of the TiNb2O7 charge-trapping nano-layer in a memory device can reach as high as 6.06 V. The larger memory window of the TiNb2O7 nano-layer is because of a better electrical and structural performance, compared to the Nb2O5 nano-layer

Characterization of Piezoresistive PEDOT:PSS Pressure Sensors with Inter-Digitated and Cross-Point Electrode Structures

The piezoresistive characteristics of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) pressure sensors with inter-digitated (IDE) and cross-point electrode (CPE) structures have been investigated. A small variation of the resistance of the pressure sensors with IDE without bottom indium-tin-oxide (b-ITO) film and with CPE structures was observed owing to the single carrier-conducting pathway. For the IDE pressure sensors with b-ITO, the piezoresistive characteristics at low and high pressure were similar to those of the pressure sensors with IDE without b-ITO and with CPE structures, respectively, leading to increased piezoresistive pressure sensitivity as the PEDOT:PSS film thickness decreased. A maximum sensitivity of more than 42 kΩ/Pa was achieved. When the normal pressure was applied, the increased number of conducting points or the reduced distance between the PEDOT oligomers within the PEDOT:PSS film resulted in a decrease of the resistance. The piezoresistive pressure sensors with a single carrier-conducting pathway, i.e., IDE without b-ITO and CPE structures, exhibited a small relaxation time and a superior reversible operation, which can be advantageous for fast piezoresistive response applications