Nanoparticle Deposition System Research Articles

One-Step Dry Coating of Hybrid ZnO-WO3 Nanosheet Photoanodes for Photoelectrochemical Water Splitting with Composition-Dependent Performance.

In this study, the potential of zinc oxide (ZnO), tungsten oxide (WO3), and their composites (ZnO-WO3) as photoanodes for photoelectrochemical (PEC) water splitting was investigated. ZnO-WO3 nanocomposites (NCs) were deposited on fluorine-doped tin oxide substrates at room temperature using a one-step dry coating process, the nanoparticle deposition system, with no post-processes. Different compositions of ZnO-WO3 NCs were optimized to enhance the kinetics of the PEC water-splitting reaction. Surface morphology analysis revealed the transformation of microsized particle nanosheets (NS) powder into nanosized particle nanosheets (NS) across all photoanodes. The optical characteristics of ZnO-WO3 photoanodes were scrutinized using diffuse reflectance and photoluminescence emission spectroscopy. Of all the hybrid photoanodes tested, the photoanode containing 10 wt.% WO3 exhibited the lowest bandgap of 3.20 eV and the lowest emission intensity, indicating an enhanced separation of photogenerated carriers and solar energy capture. The photoelectrochemical results showed a 10% increase in the photocurrent with increasing WO3 content in ZnO-WO3 NCs, which is attributed to improved charge transfer kinetics and carrier segregation. The maximum photocurrent for a NC, i.e., 10 wt.% WO3, was recorded at 0.133 mA·cm-2 at 1.23V vs. a reversible hydrogen electrode (RHE). The observed improvement in photocurrent was nearly 22 times higher than pure WO3 nanosheets and 7.3 times more than that of pure ZnO nanosheets, indicating the composition-dependence of PEC performance, where the synergy requirement strongly relies on utilizing the optimal ZnO-WO3 ratio in the hybrid NCs.

Surface morphology engineering of WO3 films for increasing Li ion insertion area in electrochromic supercapacitors (ECSCs)

Two different dry deposition methods were used to deposit electrode films with different surface morphologies in relation to the performance of electrochromic supercapacitors (ECSCs): direct current (DC) magnetron sputtering and the nanoparticle deposition system (NPDS). The NPDS method, which sprays powders onto the substrate using pressure differences, deposited WO3 film with its roughness of 36 nm and its thickness of 383 nm, while the sputtered WO3 film had its roughness of 3 nm and its thickness of 262 nm. Due to its dramatic difference in surface roughness, the NPDS-WO3 thin film had larger reaction surface area as well as Li-ion diffusion coefficient than those of sputtered-WO3 films. As a result, the ECSC device with NPDS-WO3 exhibited 19 % higher coloration efficiency with greater charge capacity compared to those with sputtered-WO3. However, the ECSC device with NPDS-WO3 showed different charge/discharge with trapped Li ions during the coloring(charging)/bleaching(discharge) processes respectively, leading to rapid degradation of the device. This research highlights the clear difference between its characteristics of the thin films fabricated using the NPDS vs. sputtering methods in relation to its surface roughness so that this study would be potentially beneficial in engineering various properties of ECSC devices.

Dynamic smart window over the entire solar spectrum using a dry deposited device for sustainable architecture

We developed a dynamic smart window capable of demonstrating transparent, black, and mirror modes across the entire solar spectrum. We demonstrated that the surface-roughness-controlled WO3 film deposited by nano particle deposition system (NPDS) can achieve the black mode with almost zero solar heat transmittance (Tsol). In the Reversible Metal Electrodeposition (RME), device can block heat similar to the mirror mode. NPDS is a unique dry deposition method to enhance the light scattering effect. As a result, the transmittance was measured in the range of the entire solar spectrum (λ ∼ 300 nm–2500 nm), obtaining 0.81% and 0.56% of Tsol for the black and mirror modes, respectively. However, 61% of Tsol was obtained for the transparent mode, confirming stark differences in Tsol. Furthermore, a dynamic smart window of 4 cm2 in size was fabricated to study the temperature change within the model house upon exposure to an infrared lamp to monitor any increase in temperature during transparent, black, and mirror modes. As a result, the temperature increases within the model house during transmittance mode increased by 19.2 °C, while the temperature increases during black and mirror modes slightly by 4.1 °C and 3.8 °C, respectively. The dynamic smart window was able to reduce the indoor temperature by more than 4.7 folds during the black/mirror modes. These findings confirmed that we developed an RME device capable of completely blocking sunlight to minimize indoor temperature change across the entire solar spectrum.

Preparation, optimization and electrochromic properties of dual-band device with four modes

A dual-band electrochromic device with four modes was fabricated to selective modulate the transmittance from visible to near-infrared bands for the energy-saving field. The new LiClO4 + TBACl + AgNO3 electrolyte was prepared to respectively regulate the redox reactions of silver ion and lithium ion to prove the four modes of the device. The dual-band device with a sandwich structure was fabricated by the titanium dioxide electrochromic film, the gallium doped zinc oxide ion storage film and the LiClO4 + TBACl + AgNO3 electrolyte. The titanium dioxide and gallium doped zinc oxide films were prepared by a nanoparticle deposition system, which is an environmentally friendly dry deposition technique. By controlling the supplied potential, the redox reactions of silver ion and lithium ion present four modes, including transparent mode, warm mode, cold mode and full block mode. For warm mode, the localized surface plasmon resonance effect was excited by generating silver nanoparticles using two-stage potential. Moreover, the titanium dioxide film with high surface roughness shown the large light scattering effect, the transmittance of ∼0% at whole wavelengths was obtained in full block mode. The electrochromic device shown the large transmittance modulation (71%) and excellent cyclic stability (600 cycles). Therefore, it is proved that the transmittance can be adjusted at a specific wavelength by the electrochromic device, which provides an effective way for developing dual-band smart devices to reduce energy consumption.

Evaluation of low-voltage-driven multi-colored electrochromic device based on dry-deposited V2O5

A V2O5 film fabricated by a nanoparticle deposition system (NPDS) was used to demonstrate a highly durable electrochromic device (ECD). The V2O5 film deposited on both the electrodes functioned as a complementary layer during the redox reaction to balance the charge inside the device. Thereby, it mitigated the load applied to the ECD by enabling its electrochromic reaction within the range of ±1 V. The fabricated ECD showing different colors at opposite voltages were applied to both the electrodes. Meanwhile, a TiO2-based opaque electrolyte was used to show different colors of V2O5 thin films independently. The fabricated ECD can display three colors: yellow, green, and blue. Furthermore, each color variation is completed within 10 s. According to the International Commission on Illumination (CIE) data, the color differences (ΔE) between yellow and green, green and blue, and yellow and blue were measured to be approximately 27, 17, and 44, respectively. Meanwhile, the fabricated ECD showed almost a similar level of electrochromic performance even after 500 repeated runs. Moreover, the charge capacity of the ECD after a 10,000-cycle cyclic voltammetry (CV) analysis was 49.01 mC/cm2 (the initial charge capacity was measured to be 47.31 mC/cm2). This verified the high durability of the device. Thus, an ECD capable of coloration under a low voltage range of ±1 V was fabricated using a dry deposition method with a TiO2-based opaque electrolyte, to vividly display different colors at both sides of the device simultaneously. The unique device can independently display different colors on both the electrodes. The dry deposition method was applied to deposit an identical V2O5 electrochromic film on the electrodes and an opaque electrolyte. The device has potential applications in functional electrochromic displays.

Room-temperature coating of Mn3O4–2D material (graphene and MoS2) nanocomposites for improving oxygen evolution reaction kinetics

Two-dimensional nanomaterials such as graphene nanosheets and molybdenum disulfide nanoflakes were easily hybridized with spinel Mn3O4 in a single deposition process at low temperature by a facile kinetic spray approach under low vacuum conditions using a nano-particle deposition system. The heterostructured Mn3O4–2D hybrid nanocomposites (NCs) were utilized to enhance the reaction kinetics of oxygen evolution. Hybrid NCs of Mn3O4 with MoS2 and graphene showed nanoflakes and nanosheet morphologies, respectively. The synergy improvement in nanocomposites of Mn3O4-graphene nanosheets and Mn3O4−MoS2 nanoflakes was examined by x-ray photoemission spectroscopy and analysis of Raman spectra that results in a decrease in OER overpotential to 289 mV at 10 mA⋅cm−2 for Mn3O4-graphene nanosheets and 295 mV for Mn3O4−MoS2 nanoflakes. The estimated Tafel slope strongly decreased from 88 mV⋅dec−1of pure Mn3O4 nanorods to around 44 mV⋅dec−1 for hybrid NCs. This behavior indicates improved charge transfer kinetics due to the decrease in charge transfer resistance. Furthermore, all fabricated nanostructure electrocatalysts exhibited very good stability for prolonged galvanostatic polarization up to 50 h.

High Optical Contrast of Quartet Dual-Band Electrochromic Device for Energy-Efficient Smart Window.

A quartet dual-band electrochromic device (ECD) was developed to selectively control the transmittance from the visible to near-infrared wavelengths for the application of an energy-efficient smart window. The new AgNO3+TBABr+LiClO4 (ATL)-based electrolyte was developed to independently control the redox reaction of lithium and silver ions to demonstrate the quartet mode of an ECD. A dual-band ECD with a sandwich structure was assembled using an ATL-based electrolyte, WO3 electrochromic layer, and antimony-doped tin oxide (ATO) ion storage layer. The employed WO3 and ATO films were fabricated using a nanoparticle deposition system (NPDS), a novel ecofriendly dry deposition method. Four modes, namely, transparent, warm, cool, and all-block modes, were demonstrated via an independent redox reaction of both lithium and silver ions through the simple control of the applied voltage. In the warm mode, the localized surface plasmon resonance effect was exploited by producing silver nanoparticles upon two-step voltage application. Furthermore, since the high surface roughness of the WO3 thin film fabricated by NPDS maximized the light scattering effect, 0% transmittance at all wavelengths was observed in the all-block mode. Dual-band ECD showed high optical contrasts of 73% and long-term durability over 1000 cycles with no degradation. Therefore, the possibility of controlling transmittance at the target wavelength was confirmed using a simple device with a simple process, suggesting a new strategy for the design of dual-band smart windows to reduce the energy consumption of buildings.

Improved Energy Efficiency of Laser-Enhanced Nanoparticle Deposition System Analyzed with a Smart Power Monitoring Device

Improved Energy Efficiency of Laser-Enhanced Nanoparticle Deposition System Analyzed with a Smart Power Monitoring Device

Evaluation of a surface roughness-dependent trimodal switchable mirror using a dry deposition method

We used a nanoparticle deposition system (NPDS) to fabricate surface roughness-dependent trimodal switchable mirrors using a non-electrochromic antimony-doped tin oxide (ATO) film with dry-deposited micro- and nano-sized ATO particles. The devices switched among transparent, mirror and black states. Reversible Ag electrodeposition onto flat ITO glass and the rough surface of the ATO film obviated the need for an electrochromic material. NPDS creates very rough films by supersonically spraying powder onto a substrate. The roughness of the micro-sized ATO film was greater than that of the nano-sized ATO film. As both films were sufficiently rough, a completely black state could be achieved by both devices (0% transmittance over the entire visible wavelength), attributable to light scattering. In contrast, the electrochemical properties of devices with the micro-sized ATO film were superior to those of devices using the nano-sized ATO film because the greater roughness increased the active surface. The charge transfer resistance of devices with the micro-sized film (38 Ω) was lower than that of devices with the nano-sized film (44 Ω). The charge capacity of devices with the micro-sized film (109.87 mC/cm2) was much higher than that of devices with the nano-sized (95.59 mC/cm2). The cyclic transmittance of the device using the micro-sized ATO film was evaluated over 500 cycles with 0% diminution for its durability. Therefore, a trimodal switchable mirror was demonstrated by controlling the surface roughness of a non-electrochromic film. • Dry deposition of particles can control surface roughness of the film. • Trimodal switchable mirror was achieved successfully without electrochromic film. • The electrode with rough surface forms complete black state by light scattering. • Performance of switchable mirror device was compared depending on surface roughness.

High-temperature mechanical and thermochemical properties of NbMoTaW refractory high-entropy alloy coatings produced via Nano Particle Deposition System (NPDS)

In this study, we investigated the oxidation resistivity and mechanical properties of NbMoTaW refractory high-entropy alloy (HEA)-based coatings at high temperatures. The coating layers were produced using mechanically alloyed HEA powders via Nano Particle Deposition System (NPDS). The as-milled powder is comprised of W-rich BCC1 and NbMoTa-rich BCC2 phases. After the deposition process, the W-rich BCC1 phase remained, while NbMoTa-rich BCC2 phases were transformed into complex NbMo-rich and Ta-rich oxides. Consequently, the NbMoTaW RHEA composite coating exhibited outstanding oxidation resistivity and high nanoindentation hardness at high temperatures compared to that of commercial coating materials, possibly owing to the combination of the W-rich solid solution phase and internal oxides.

Facile Fabrication of Trimodal Switchable Mirror Device with Zero Transmittance in the Black State

AbstractThe electrochromic mirror device (ECD) demonstrating transparent, mirror, and black states with zero transmittance in the black state is fabricated using facile dry deposition method. The device is capable of achieving both a highly reflective mirror and a complete black state. ECD is fabricated using a WO3 film deposited by nanoparticle deposition system (NPDS) and optical characteristics of its transparent, mirror, and black states are evaluated. Notably, the device demonstrates the mirror state with high reflectance over 80% and a black state that completely blocks the entire visible light, resulting in nearly zero transmittance. Device durability is evaluated over 100 cycles; the transmittance of the black and transparent states is measured to be 9.61%, 79.6% at its wavelength of 680 nm, respectively. Moreover, the reflectance of the mirror state at the same wavelength is measured to be 73.1% and 72.7% for the first and 100th cycles, respectively. Microstructural observations suggest that the visible light‐blocking effect is a consequence of the rough surface obtained using NPDS, which leads to uneven electrodeposition of Ag ions to produce localized surface plasmon resonance. Dry deposition method of the electrochromic layer is an excellent method for fabricating high‐contrast three‐mode electrochromic mirrors.

One-step deposition of a Ni(OH)2-graphene hybrid prepared by vacuum kinetic spray for high energy density hybrid supercapacitor

Hybrid supercapacitors (HSCs) that use the nickel hydroxide-graphene hybrid (NGH) as an anode material and reduced graphene oxide (rGO) as a cathode material are a promising HSC structure. The NGH electrode is synthesized by one-step, binder-free deposition of a micro-size hydroxide powder and graphite powder mixture on nickel foam by the nanoparticle deposition system (NPDS). The NPDS is classified as a vacuum kinetic spraying approach. The electrochemical performance of the NGH-10 electrode in a 3-electrode cell demonstrates a specific capacitance of 3408 F/g at 1 A/g. The NGH-10//rGO HSC displays a specific capacitance of 180 F/g at 1 mA/cm2 in a high operating potential from 0 V to 1.6 V. The NGH-10//rGO HSC has an energy density of 64 Wh/kg @ 411 W/kg, and still 20 Wh/kg @ 8230 W/kg.

One Million Cycle Durability Test of Electrochromic Devices Using Charge Balance Control

We fabricated 10 mm × 10 mm WO3 electrochromic devices (ECDs) using a nanoparticle deposition system (NPDS), which is a coating method that uses kinetic spray. NPDS has the advantage of mass production due to its relatively low pressure and low temperature working conditions but can result in porous surfaces, which has a negative effect on device durability. We developed an optical transmittance measurement and voltage control system that allows dynamic control. Transmittance was measured by Optical Power Meter, 2936-R Newport, while voltage was dynamically applied by NI9477, National Instrument. Current was measured by high resolution current, National Instrument. This system enables ECDs to be feedback controlled depending on the measured electronic properties. We then characterized the WO3 ECDs, focusing on the relationship between transmittance and current under well-known static operating conditions. Finally, we proposed a new algorithm to extend durability performance by adopting charge balance control and conducted an accelerated life test over 1,000,000 cycles. According to our results, the optical performance was maintained until the test ended, and there was a 45.4% difference in the maximum and minimum transmittance of the sample after the accelerated life test. Therefore, the charge balance control enhanced the lifetime of the ECDs by avoiding negative charge accumulation, verifying that the durability of ECDs could be enhanced by adopting dynamic control.

Deposition of Ni(OH)2 on nickel substrate using vacuum kinetic spray and its application to high-performance supercapacitor

Herein, we report a direct deposition of nano-structured Ni(OH)2 from micro-sized Ni(OH)2 powder on nickel sheet and nickel foam using nano-particle deposition system, one of the low-vacuum and room temperature vacuum kinetic spray processes. In this work, the deposition of the Ni(OH)2 powder on nickel sheets is carried out with various stand-off-distances (SoDs) and carrier gas pressures. The deposited films are investigated by field-emission electron microscopy, X-ray diffraction, and Raman spectroscopy. The crystallite size of the nano-structured Ni(OH)2 depends on the SoD and the carrier gas pressure. The electrochemical performance of Ni(OH)2 deposited on nickel sheets is measured by cyclic voltammetry in the 3-electrode cell. The deposition with 5 mm SoD and 0.3 MPa carrier gas pressure is found to be the optimum deposition condition for the nano-structured Ni(OH)2 thin film as an electrode material. The nano-structured Ni(OH)2 thin film deposited with 5 mm SoD and 0.3 MPa carrier gas pressure on nickel foam demonstrates a specific capacitance of 2377 F g−1 at 2 mV s−1 scan rate and 2092 F g−1 at 1 A g−1 current density and excellent cyclic stability for 3000 cycles with 83% capacitance retention.

All-Solid-State Supercapacitor Based on MoS2–Graphite Composite Prepared by the Vacuum Kinetic Spray Method

The combination of the molybdenum disulfide (MoS2) and graphite can result in very promising hybrid electrode material for use in energy storage devices owing to the interesting properties of the combined material, such as an extremely high surface area, and prominent electrical conductivity. In this study, MoS2 powder and graphite powder are mixed with different compositions via the ball milling. A nanoparticle deposition system is used to deposit MoS2–graphite composites on stainless-steel. The morphology and structure of the thin films are evaluated by field-emission scanning electron microscope, x-ray diffraction, and Raman spectroscopy. The electrochemical performances of supercapacitors fabricated from MoS2–graphite thin films as an electrode material using a two-electrode cell were evaluated by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The supercapacitor shows better performance at 15% of the MoS2–graphite composition ratio. Moreover, the cyclic stability of the supercapacitor is measured by repeating charging–discharging for 10,000 cycles.

Photocatalytic performance of few-layer Graphene/WO3 thin films prepared by a nano-particle deposition system

Abstract The nano-particle deposition system (NPDS) is an environmentally friendly, room temperature, dry particle deposition technique to impart thin films of metal or ceramic particles onto different substrates without any additional chemicals. In this work, graphite and WO3 powders with different graphite contents (0–30 wt%) were successfully deposited on a polypropylene substrate by an NPDS without generating any thermal damage of the substrate. The graphite particles can easily be fragmented into small few-layer graphene nano-flakes along with WO3 utilizing the high kinetic energy during NPDS. With field emission scanning electron microscopy, fragmentation of particles due to the high impact velocity of the powders during deposition was observed. X-ray diffraction showed the absence of any graphite peak in the composite thin film. Finally, the existence of few-layer graphene in the fabricated thin film was confirmed by Raman spectroscopy. To evaluate the photocatalytic activity of the fabricated thin films, degradation of methylene blue dye under illumination of light for 2 h was observed. Degradation of the dye was evaluated using absorbance values measured by UV/Vis spectroscopy before and after the test. The results showed that the photocatalytic performance was significantly enhanced when the WO3 contained added graphite and suggested that 15 wt% of graphite was the optimal level in the composite thin film. The photocatalytic reaction followed pseudo-first-order kinetics. Repeatability determines the feasibility of thin films in using real applications. Here, all the thin films showed good stability up to five cycles. The few-layer graphene/WO3 composite thin films were easily prepared for the photocatalytic application using NPDS.

Electrochemical Performance of Few-Layer Graphene Nano-Flake Supercapacitors Prepared by the Vacuum Kinetic Spray Method

A few-layer graphene nano-flake thin film was prepared by an affordable vacuum kinetic spray method at room temperature and modest low vacuum conditions. In this economical approach, graphite microparticles, a few layers thick, are deposited on a stainless-steel substrate to form few-layer graphene nano-flakes using a nanoparticle deposition system (NPDS). The NPDS allows for a large area deposition at a low cost and can deposit various metal oxides at room temperature and low vacuum conditions. The morphology and structure of the deposited thin films are alterable by changing the scan speed of the deposition. These changes were verified by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. The electrochemical performances of the supercapacitors, fabricated using the deposited films and H3PO4–PVA gel electrolytes with different concentrations, were measured using a 2-electrode cell. The electrochemical performance was evaluated by cyclic voltammetry, galvanostatic Charge–discharge, and electrochemical impedance spectroscopy. The proposed affordable fabricated supercapacitors show a high areal capacitance and a small equivalent series resistance.

Investigation of Varying Particle Sizes of Dry-Deposited WO3 Particles in Relation to Performance of Electrochromic Cell

Electrochromic cells were fabricated via a nanoparticle deposition system (NPDS) using different particle sizes of monoclinic tungsten oxide (WO3). Mixtures of micro- and nano-sized WO3 powders in the ratios of WO3 (micro):WO3 (nano) = 9:1, 5 : 5 and 1 : 9 vol%, were used in this study. NPDS, which was used to fabricate the electrochromic layer, is a low-cost process that can cover a large deposition area and provides a highly porous film. This method can replace sol-gel and sputtering methods, which are expensive and have environmental issues. The WO3 electrochromic layers displayed different surface structures that could adsorb Li+ ions. The transmittance change, cyclic switching speed and coloration efficiency (CE) results demonstrated that the electrochromic cell made with the mixed WO3 (micro):WO3 (nano) powders had better performance than that of the electrochromic cell made with separate micro-sized single powders. Various analyses showed that the WO3 mixed powders contained larger sites for Li+ ion adsorption compared with the single-sized powder because of a structure consisting of a compact layer of micro-WO3 with a porous layer of nano-WO3. Consequently, a cell composed of mixed-particle electrochromic layer showed higher transmittance change, CE and electrochromic performance than a cell made with a micro-sized single powder.

Kinetic spraying of silver nanowire blended graphite powder to fabricate transparent conductive electrode and their application in electrochromic device

A transparent conductive electrode (TCE) using the mxiture of graphite and silver nanowires (AgNWs) powder was fabricated with a nanoparticle deposition system (NPDS), a facile dry deposition approach using a graphite-AgNW powder mixture. The deposited film formed a composite structure with few-layered graphene, single layered graphene sheets, and AgNWs forming a fused junction under optimal heat treatment at 80 °C. The sheet resistance of the deposited film was measured to be 24–28 Ω/□, in accordance with values measured for commercial TCEs. Transmittance of 58–67% was measured for the deposited sample, which was lower than the 20–30% measured for conventional TCEs, due to scattering of incident light by few-layered graphene and AgNWs within the deposited film. An electrochromic (EC) cell with fabricated TCE performed well, showing a transmittance change of 15% at its wavelength of 630 nm. CV measurements were conducted for 500 cycles to confirm the stability of the EC device and TCE, and no performance degradation was observed for the device after 500 cycles, which represents good cyclic stability. Therefore, a TCE using graphite and AgNWs was successfully fabricated using the facile NPDS process, which represents a new fabrication process for TCEs based on graphene and AgNWs.

Ultra-High Vacuum Fabrication of Ordered Nanoparticles and Their Device Applications

Nanoparticles are important for the implementation of a variety of photonic and electronic devices with new functionalities and improved performances. While multiple photonic devices using nanoparticles have been successfully implemented, the use of nanoparticles in electronic devices have significantly lagged; one of the primary reasons being the more stringent material and surface purity requirements for such devices. While the feasibility of a variety of electronic devices based on nanoparticles have been demonstrated in the laboratory, such as nanoparticle flash memory and single electron transistors, the fabrication technique employed is electron-beam lithography, which unfortunately is not suitable for large scale manufacturing. For most electronic devices, it is typically required that the nanoparticle dimensions be in the 1 nm to 10 nm range with size variations of 10% or less. Current photolithographic techniques are not suitable for the implementation of such nanoparticles, and nonlithographic techniques are typically used for their fabrication. However, most nonlithographic techniques are based on natural self-organization processes and suffer from a lack of flexibility or a lack of engineering control. Among the various nonlithographic techniques, the predominant ones are solution based, examples of which include sol-gel synthesis, chemical synthesis, and electrochemical synthesis inside self-organized nanoporous templates. While such solution based techniques can produce nanoparticles with the required dimensions and size distributions, they also need complex surface passivation involving capping molecules to prevent aggregation. These capping molecules modify the electrical surface properties of the nanoparticles making charge injection/extraction difficult. In addition, the solution based synthesis techniques are not compatible with the silicon integrated circuit (IC) process, in particular the Complementary Metal Oxide Silicon (CMOS) process, which is the predominant manufacturing process for electronic devices. It is widely believed that the availability of a CMOS compatible nanoparticle fabrication technique can greatly increase the viability of nanoparticle based electronic devices. We have developed a CMOS compatible ultra-high vacuum system for the implementation of nanoparticle based electronic devices that addresses the above issues. The system consists of (i) a nanoparticle unit that provides the capability to deposit nanoparticles of any metal, semiconductor or insulator of diameters as low as 1 nm with less than 5% size variation on an arbitrary substrate, (ii) a 4-pocket electron-beam evaporation unit that allows the in-situ deposition of four different materials (metals or insulators) with less than 5% thickness uniformity, and (iii) a UHV pulsed DC sputter source that allows the in-situ deposition of thick layers of insulators (semiconductors or metals) including isolation dielectrics. The nanoparticle deposition unit, the ohmic contact metallization unit and the isolation dielectric deposition unit are all housed inside an ultra-high vacuum (10-10 torr) chamber to ensure high purity and good surface properties of the nanoparticles. The nanoparticle deposition system is based on sputtering, thus making it possible to deposit nanoparticles of any material that can be sputtered. In addition, nanoparticle deposition can be carried out at room temperature, making it possible to deposit the nanoparticles on a variety of substrates including flexible substrates. Size selection of nanoparticles is achieved by using a quadrupole mass filter with the capability to provide as low as 2% size control. One advantage of the system is that ohmic contacts and isolation dielectrics can be formed in an integrated manner without breaking vacuum, which is important for electrical continuity. In addition, the deposited nanoparticles can be embedded in, or coated with, metallic, semiconducting or insulating layers without breaking vacuum, thus making complex multi-layered structures possible that can have applications in a variety of fields including nanoscale detectors, nano-optics, nano-sensors, field-emitters etc. For nanoparticle based electronic devices to function properly, it is essential that the nanoparticles are physically separated from each other. In addition, if the nanoparticles can be ordered in a periodic manner, it can significantly improve device reliability and performance. To address these issues, we have developed a technique for the electrical ordering of the nanoparticles that can be carried out in-situ without breaking vacuum. The ordering process is rapid, does not require physical contact with nanoparticles and thus prevents contamination. We have used the system and technique for the deposition of a variety of nanoparticles of metals and semiconductors including Ni, Fe, Co, Au, Ag, Cu, Si, CdTe, CdSe, ZnS on a variety of substrates including silicon, silicon dioxide coated Si, metal coated silicon, quartz, sapphire. We have also fabricated complex structures containing nanoparticles for various applications In this presentation, we will provide details of the apparatus, fabrication process, experimental results as well some of the nanoparticle based electronic devices currently being developed.