- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Direct Imaging of Current‐Induced Transformation of a Perovskite/Electrode Interface
摘要： Formamidinium-lead-iodide (FAPbI3) perovskite films are subjected to a long-term action of the constant electrical current in the dark, using planar vacuum-deposited gold electrodes. The current-induced transformation is monitored by the time-of-flight secondary ion mass spectrometry (ToF-SIMS) mapping complemented by microscopic, spectroscopic methods, and X-ray diffraction. The migration of chemical species inside the lateral interelectrode gap is clearly visualized by ToF-SIMS. Those species correspond to both electrode material and perovskite itself, so that the perovskite/electrode interface becomes disrupted. As a result, the interelectrode gap shrinks, which is reflected in the surface images.
关键词： interfaces,dark current,gold electrodes,perovskites,ToF-SIMS mapping
更新于2025-11-25 10:30:42
-
Origin of anisotropy and compositional dependence of phonon and electron transport in ZnO based natural superlattices and role of atomic layer interfaces
摘要： Reaction of ZnO with trivalent ions can form natural superlattice (SL) compounds, which possess unusual structural characteristics and strong anisotropic physical transport properties. In this work, by synthesizing strongly textured bulk polycrystals of pure SL phases and performing characterization and measurements for both in-plane and cross-sectional directions, we revealed the strongly crystal orientation dependent transport properties. The observed compositional or SL interface spacing dependent electrical conductivity is largely attributed to the overall doping of ZnO wurtzite regions. The atomic layer SL interfaces are phonon barriers, and the interfacial thermal (Kapitza) resistance depends on SL interface spacing. The transport direction perpendicular to these SL interfaces are electron-conductive paths with remarkably higher electron mobility. There are electron potential barriers associated with these atomic layer SL interfaces. The effective and absolute potential barrier heights are determined, which are proportional to the natural conduction band discontinuities. The current study provides new findings and knowledge about the role of SL interfaces in phonon and electron transport process in these ZnO based natural SLs. The present work can be useful and inspiring to design and modify complex layer-structured compounds, including synthetic superlattice systems, for a variety of applications where energy carriers transport is involved.
关键词： Interfaces,Superlattices,Electron potential barrier,Interfacial thermal (Kapitza) resistance,Thermal conductivity,ZnO
更新于2025-11-21 11:03:13
-
Facile Interface Self-Assembly of Gold Nanoparticles as Surface-Enhanced Raman Scattering Substrate for Monitoring the Reduction of p-Nitrophenol
摘要： A facile interface self-assembly method was proposed to fabricate the gold monolayer film without any specific molecular cross-linkers. The film was served as a surface-enhanced Raman scattering substrate, which exhibited high enhancement and reproducibility to the 1 × 10-9 M rhodamine 6G aqueous solution. Based on the substrate, the in situ and real-time monitoring for the reduction of p-nitrophenol to p-aminophenol was demonstrated successfully.
关键词： Interfaces,Surface-enhanced Raman scattering,Self-assembly,Nanoparticles
更新于2025-11-14 17:03:37
-
Copper sulfide nanoparticles as hole-transporting-material in a fully-inorganic blocking layers n-i-p perovskite solar cells: Application and working insights
摘要： One of the challenges in the field of perovskite solar cells (PSC) is the development of inorganic hole-transporting-materials (HTM) suitable for solution-processed deposition, in order to have cheaper, more stable and scalable devices. Herein, we report the synthesis and characterization of p-type copper sulfide nanoparticles for their application for the first time as a low-cost, fully-inorganic HTM in mesoscopic n-i-p PSC. By employing CuS combined with two different perovskites, CH3NH3PbI3 (MAPbI3) and (FAPbI3)0.78(MAPbBr3)0.14(CsPbI3)0.08 (CsFAMAPbIBr), very high current densities and fill-factors are observed, suggesting an effective hole-extraction happening at the CuS interface. Noticeable, our cells exhibit one of the highest power conversion efficiencies (PCE) in n-i-p configuration employing a sole solution-processed inorganic HTM via non-toxic solvents, leading to 13.47% and 11.85% for MAPbI3 and CsFAMAPbIBr, respectively. As a remark, such PCE values are only limited by a reduced open-circuit voltage around 0.8 V, due to different phenomena occurring at perovkite/CuS interface such as an increased non-radiative recombination, caused by considerable difference in valence band value, and the effect of CuS metallic character. Overall, these findings highlight CuS as an extremely cheap alternative to common organic HTMs and pave the way to new improvements employing this material in full-inorganic blocking layers PSC.
关键词： perovskite solar cells.,Copper sulfide,interfaces,inorganic hole-transporting-material
更新于2025-10-22 19:40:53
-
[IEEE 2018 IEEE Biomedical Circuits and Systems Conference (BioCAS) - Cleveland, OH, USA (2018.10.17-2018.10.19)] 2018 IEEE Biomedical Circuits and Systems Conference (BioCAS) - Wireless Power and Data Link for Ensembles of Sub-mm scale Implantable Sensors near 1GHz
摘要： We describe a custom wireless power and data transmission (WPDT) link and analyze its performance in a prototype implantable sensor system of ensembles of CMOS sensor ASICs (“Neurograins”) embedding 0.5 mm x 0.5 mm planar microcoil antennas. We use near-field RF at ~1 GHz for wireless powering in a resonant 3-coil architecture including an implanted relay coil in a quadrant layout architecture to maximize coverage area and RF transfer efficiency. We demonstrate successful WPDT across antenna cross-section in benchtop proxy physiological tests. Demodulation and analysis of backscattered signals validate the data link fidelity. Our results suggest that this electromagnetic coupling scheme can robustly support a chip density of 250/ cm2 (up to 1024 individual Neurograins in a 2 cm x 2 cm area) and parallel transmitters can be combined to multiply the channel capacity without destructive interference.
关键词： wireless power,brain-computer interfaces,brain-machine interfaces,implantable sensors
更新于2025-09-23 15:23:52
-
A Concept for Molecular Addressing by Means of Far-reaching Electromagnetic Interactions in the Visible
摘要： A pronounced concentration dependence of the time constant of fluorescence decay was found, disproving Strickler-Berg’s equation restricting molecular light emission to a local process. Thus, interactions were found significantly extending to more than 100 nm and make such systems promising for interfaces between molecular dots or more complex molecular arrangements and conventional macroscopic electronics.
关键词： Interfaces,Fluorescence,Strickler-Berg-equation,Molecular electronics
更新于2025-09-23 15:23:52
-
Computational Study on Interfaces and Interface Defects of Amorphous Silica and Silicon
摘要： The amorphous SiO2/Si interface is arguably the most important part in semiconductor technology, strongly influencing the device reliability. Its electronic structure is affected by the defects, majorly the dangling bonds known as Pb-type defects, which have been studied for decades. These defects are usually passivated by hydrogen atoms in device processing, which eliminates the defect levels in the silicon bandgap and thus removes their electric activity. However, when the interface is exposed to ionization radiation, the passivated defects can be reactivated by the protons generated by radiation, which significantly affects the device performance and causes reliability issues. In this review, computational studies on the amorphous SiO2/Si interface and interface defects are summarized, including the modeling of the interface, the main interface defects, and their depassivation, and compared to experimental results. The hyperfine parameters are emphasized, because they are essential to identify the structures of the interface defects. The defect levels and depassivation of the defects are also emphasized, because the former directly affect the device performance and the latter directly generates the dangling bonds in the interface.
关键词： depassivation,ionizing damage,interface defects,amorphous interfaces,first-principles calculations
更新于2025-09-23 15:23:52
-
Optical and interface characteristics of Al0.56Ga0.44N/Al0.62Ga0.38N multiquantum wells with ～280?nm emission grown by plasma-assisted molecular beam epitaxy
摘要： We have investigated the nature of Al0.56Ga0.44N/Al0.62Ga0.38N multiquantum wells grown by plasma-assisted molecular beam epitaxy for application in deep-ultraviolet light emitters. Excitation and temperature-dependent and time-resolved photoluminescence measurements and transmission and reflectance spectroscopy have been complemented by high-angle annular dark field scanning transmission electron microscopy. The 3nm quantum wells are characterized by interface roughness having a height of 0.3-1nm and the maximum value is in excellent agreement with values obtained from calculations done to analyze the measured photoluminescence lineshape. The radiative lifetime increases with temperature, suggesting the role of electron-hole scattering to cool photoexcited carriers to the ground state of the quantum wells.
关键词： A1. Interfaces,B1. Nitrides,A3. Quantum wells,A3. Molecular beam epitaxy
更新于2025-09-23 15:23:52
-
Diluted Oxide Interfaces with Tunable Ground States
摘要： The metallic interface between two oxide insulators, such as LaAlO3/SrTiO3 (LAO/STO), provides new opportunities for electronics and spintronics. However, due to the presence of multiple orbital populations, tailoring the interfacial properties such as the ground state and metal-insulator transitions remains challenging. Here, an unforeseen tunability of the phase diagram of LAO/STO is reported by alloying LAO with a ferromagnetic LaMnO3 insulator without forming lattice disorder and at the same time without changing the polarity of the system. By increasing the Mn-doping level, x, of LaAl1?xMnxO3/STO (0 ≤ x ≤ 1), the interface undergoes a Lifshitz transition at x = 0.225 across a critical carrier density of nc = 2.8 × 1013 cm?2, where a peak TSC ≈255 mK of superconducting transition temperature is observed. Moreover, the LaAl1?xMnxO3 turns ferromagnetic at x ≥ 0.25. Remarkably, at x = 0.3, where the metallic interface is populated by only dxy electrons and just before it becomes insulating, a same device with both signatures of superconductivity and clear anomalous Hall effect (7.6 × 1012 cm?2 < ns ≤ 1.1 × 1013 cm?2) is achieved reproducibly. This provides a unique and effective way to tailor oxide interfaces for designing on-demand electronic and spintronic devices.
关键词： anomalous Hall effect,2D electron liquid,oxide interfaces,superconductivity,metal-insulator transitions
更新于2025-09-23 15:23:52
-
Electronic properties of hybrid organic/inorganic semiconductor pn-junctions
摘要： Hybrid inorganic/organic semiconductor heterojunctions are candidates to expand the scope of purely organic or inorganic junctions in electronic and optoelectronic devices. Comprehensive understanding of bulk and interface doping on the junction’s electronic properties is therefore desirable. In this work, we elucidate the energy level alignment and its mechanisms at a prototypical hybrid pn-junction comprising ZnO (n-type) and p-doped N,N′-di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (α-NPD) as semiconductors, using photoelectron spectroscopy. The level alignment can be quantitatively described by the interplay of contact-induced band and energy level bending in the inorganic and organic component away from the interface, and an interface dipole due to the push-back effect. By adjusting the dopant concentration in α-NPD, the position of the frontier energy levels of ZnO can be varied by over 0.5 eV and that of α-NPD by over 1 eV. The tunability of this pn-junction’s energy levels evidences the substantial potential of the hybrid approach for enhancing device functionality.
关键词： semiconductors,electronic properties,photoelectron spectroscopy,interfaces
更新于2025-09-23 15:23:52