- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
The Synthesis of Mesoporous Sio2/Tio2 Composite Particles by Sol-Gel Method and Effect of Hexane on its Structural Properties
摘要： Due to their unique properties such as high surface area, uniform and adjustable pore structure, and permeability of various molecules within and on their surface, mesoporous materials have become of interest in various fields including electronics, separation, catalysis, medical applications such as implant coatings and drug delivery. Mesoporous SiO2/TiO2 particles were synthesized by sol-gel method using various amounts of surfactant cetyl tri methyl ammonium bromide (CTAB) as structure directing agent under acidic condition; moreover, hexane was applied as a swelling agent. The samples were investigated using XRD, SEM, FTIR, SEM and N2 adsorption-desorption analyses, in addition, the incremental effect of surfactant and hexane were examined. The results obtained from the analysis clarified that an increase in amount of surfactant will lead to an increase in surface area, pore size and pore volume. Additionally, with adding hexane to the constant amount of surfactant; the results showed an increase in surface area, pore size and pore volume while order of the structure was maintained.
关键词： Mesoporous,Swelling agent,N2 adsorption-desorption,Surfactant
更新于2025-09-23 15:22:29
-
X-ray Photoelectron Spectroscopy Analysis of the Effect of Photoresist Passivation on InGaZnO Thin-film Transistors
摘要： Bottom-gate InGaZnO (IGZO) thin-film transistors (TFTs) with EOC photoresist (PR) passivation were fabricated. Compared to the unpassivated IGZO TFT with a mobility of 6.71 cm2V-1s-1, a hysteresis of 2.42 V and a poor bias stress stability, the PR-passivated IGZO TFT showed good electrical characteristics with a higher mobility of 8.85 cm2V-1s-1, a lower hysteresis of 0.06 V and a more reliable stability (△Vth = 0.36 V) under positive gate bias stress (PBS). The effect of PR passivation on the performance of IGZO-TFT was investigated by x-ray photoelectron spectroscopy (XPS), systemically. The result of XPS spectra of the O 1s core levels indicate that PR passivation effectively suppressed the adsorption/desorption effect on IGZO surface, resulting in fewer unstable states and higher electrical stability. Furthermore, XPS depth profile experiments show that the proportion of elements on the film surface changed and the IGZO surface was In-rich after PR passivation, enhancing the mobility. The PR passivation with low temperature (100 oC) process exhibited good dielectric quality and excellent barrier ability against water and oxygen molecules. Therefore, it may be a good candidate for high-mobility and high-stability flexible TFTs in future.
关键词： XPS,InGaZnO,Photoresist,Thin film transistors,Adsorption/desorption
更新于2025-09-23 15:21:21
-
Bare Silica Opals for Real-Time Humidity Sensing
摘要： The photonic properties of 3D colloidal crystals made of St?ber silica spheres are shown to significantly depend on the relative humidity of the environment. The photonic bandgap of bare artificial opals formed by hydrophilic silica markedly varies in humid air along the entire range of water vapor concentration without the need for infiltration of functionalization. The optical changes are highly sensitive to humidity variation (especially in low-humidity range) and very fast response times of 60 ms, mainly ascribed to the absence of intermediate processes, the favorable bandgap characteristics (high intensity and sharp edges) and the high air accessibility to the open opal voids. Contrary to common approaches for photonic crystal sensors—seeking visual detection via large spectral shifts but having important shortcomings,—it is demonstrated that the well-defined photonic bandgap of bare silica opals allows, even for moderate shifts, outstanding sensing performance by proper monitoring with inexpensive equipment (no spectroscopic detection is needed). As a result, the rapid and reproducible photonic response enables accurate, real-time retrieval of the ambient humidity. The economical, one-step fabrication, and the efficient performance make silica artificial opals suitable for a new type of precise, low-cost, and real-time humidity sensors.
关键词： water vapor adsorption/desorption,real-time sensing,humidity sensors,artificial silica opals,photonic colloidal crystals
更新于2025-09-23 15:21:01
-
Exploring the surface chemistry of cesium lead halide perovskite nanocrystals
摘要： Colloidal nanocrystals (NCs) of cesium lead halide perovskites (CsPbX3, X = Cl, Br or I) are emerging as an exciting class of optoelectronic materials, but the retention of their colloidal and structural integrity during isolation, purification and handling still represents a critical issue. The impelling questions concerning their intrinsic chemical instability are connected to the dynamic nature of the bonding between the inorganic surface and the long-chain capping ligands. However, the key aspects of CsPbX3's surface chemistry that directly impact their stability remain elusive. In this contribution, we provide an in-depth investigation of the surface properties of differently composed CsPbX3 NCs, prepared by traditional hot-injection methods. The study, mainly relying on solution NMR spectroscopy, is backed up by elemental analysis as well as morphological, structural and optical investigations. We ascertained that the nature of the ligand adsorption/desorption processes at the NC surface is dependent on its elemental composition, thus explaining the origin of the instability afflicting CsPbI3 NCs. We also evaluated the effect of NC purification as well as of the degradation pathways involving the organic shell on the surface chemistry of CsPbX3 NCs. This study paves the way for new post-functionalization strategies for this promising class of nanomaterials.
关键词： surface chemistry,colloidal stability,degradation pathways,cesium lead halide perovskite nanocrystals,purification,ligand adsorption/desorption,NMR spectroscopy
更新于2025-09-19 17:15:36