Silicon carbide (SiC), with its wide bandgap and strong resistance to radiation and thermal conditions, is a promising material for ultraviolet (UV) photodetector applications under harsh environments. In this study, porous SiC thin films with thicknesses of 20, 50, and 80 nm were fabricated on 4H-SiC substrates using aerosol deposition (AD), which enables roomtemperature film formation. The device with a 50 nm-thick film exhibited the highest photoresponse under UV-C illumination (260 nm), achieving a maximum photo-to-dark current ratio (PDCR) of 205.2, a responsivity of 0.058 A/W, an external quantum efficiency (EQE) of 27.71%, and a specific detectivity (D*) of 7.9×10¹¹ Jones. These results are attributed to an optimized balance between photon absorption and carrier transport in the porous structure. The findings confirm the potential of ADfabricated porous SiC films for highly sensitive and scalable UV photodetector applications.

Metal halide perovskites (MHPs) have attracted attention as new display materials due to their excellent optical properties, but their application is limited by the complexity of conventional synthesis methods and the film formation processes. As an alternative, color conversion film fabricated via the aerosol deposition (AD) process using CsPbBr₃/Al₂O₃ powder, a ceramic matrix-based MHP composite, has expanded the practical utility of MHPs by simplifying both the synthesis and film formation steps. Nevertheless, the hammering effect that occurs during the AD process can damage the MHP crystal structure, leading to degradation of its optical properties. Therefore, in this study, to overcome the problem of optical degradation, we compared the structural and photoluminescence (PL) properties of films fabricated by adding polytetrafluoroethylene (PTFE), a material with a buffering effect, to the CsPbBr₃/Al₂O₃ starting powder at mass ratios of 0, 0.1, 0.5, 1, and 2 wt% to mitigate the hammering effect. The film containing 1 wt% PTFE exhibited the highest PL performance, achieving a luminous efficiency of 52.1 lm/W. This improvement is attributed to PTFE providing an optimal buffering effect without forming aggregates on the film surface. These results further enhance the applicability of AD-based color conversion films and are expected to contribute to the development of high-resolution display technologies.

Dielectric ceramic capacitors present high output power density due to the fast energy charge and discharge nature of dielectric polarization. By forming dense ceramic films with nano-grains through the Aerosol Deposition (AD) process, dielectric ceramic capacitors can have high dielectric breakdown strength, high energy storage density, and leading to high power density. Dielectric capacitors fabricated by AD process are expected to meet the increasing demand in applications that require not only high energy density but also high power output in a short time. This article reviews the recent progress on the dielectric ceramic capacitors with improved energy storage properties through AD process, including energy storage capacitors based on both leadbased and lead-free dielectric ceramics.

Citations

• Single-Molecule Manipulation Techniques Based on Mechanical, Electrical, and Structural Control
  Jeong Hun Shin, Tae Won Nam
  Journal of Electrical and Electronic Materials.2026; 39(3): 247.     CrossRef

Energy storage capacitors based on dielectric ceramics with superior polarization properties and dielectric constant can provide much higher output power density due to their very fast energy charging/discharging rates, which are particularly suitable for operating pulsed-power devices. For an outstanding energy storage performance of dielectric capacitor, a large recoverable energy density could be derived by introducing a slim polarization-electric field hysteresis loop into dielectric materials by various technical approaches. Many research teams have explored various dielectric capacitor technologies to demonstrate high output power density and ultrafast charging/discharging behavior. This article reviews the recent research progress in high-performance dielectric capacitors for pulsed-power electronic applications.

Capacitive-type humidity sensors with a high sensitivity and fast response/recovery times have attracted a great attention in non-contact respiration biological signal monitoring applications. However, complicated fabrication processes involving high-temperature heat treatment for the hygroscopic film is essential in the conventional ceramic-based humidity sensors. In this study, a non-toxic ceramic/metal halide (BaTiO₃(BT)/NaCl) humidity sensor was prepared at room temperature using a solvent-free aerosol deposition process (AD) without any additional process. Currently prepared BT/NaCl humidity sensor shows an excellent sensitivity (245 pF/RH%) and superior response/recovery times (3s/4s) due to the NaCl ionization effect resulting in an immense interfacial polarization. Furthermore, the non-contact respiration signal variation using the BT/NaCl sensor was determined to be over 700% by maintaining the distance of 20 cm between the individual and the sensor. Through the AD-fabricated sensor in this study, we expect to develop a non-contact biological signal monitoring system that can be applied to various fields such as respiratory disease detection and management, infant respiratory signal observation, and touchless skin moisture sensing button.

Controlling ambient humid condition through high performance humidity sensors has become important for various fields, including industrial process, food storage, and the preservation of historic remains. Although aerosol deposited humidity sensors using ceramic BaTiO₃ (BT) material have been widely studied because of their longtime stability, there remain critical disadvantages, such as low sensitivity, low linearity, and slow response/recovery time in case of the sensors fabricated at room temperature. To achieve superior humidity sensing properties even at room temperature condition, BT-Cu composite films utilizing aerosol deposition (AD) process have been proposed based on the percolation theory. The BT-Cu composite films showed gradually improved sensing properties until the Cu concentration reached 15 wt% in the composite film. However, the excessive Cu (above 30 wt%) containing BT-Cu composite films showed a rapid decrease of the sensing properties. The results of observed surface morphology of the AD fabricated composite films, to figure out the metal filler effect, showed correlation between surface topography as well as size and the amount of open pores according to the metal filler content. Overall, it is very important not only dielectric constant of the humidity sensing films but also microstructures, because they affect either the variation range of capacitance by ambient humidity or adsorption/desorption of ambient humidity onto/from the humidity sensing films.

Four types of BaTiO₃ powders are prepared and successfully deposited on glass and Pt/Si substrates using the aerosol deposition process. Particles with sizes of 0.45 μm and 0.3 μm are selected as the starting powder, while those powders are treated using a different milling method. The jet-milled and ball-milled powders not only showed a smaller particle-size distribution, but compared with the non-milled powder, it also had a higher deposition rate using the uniformly generated aerosol. Although the films deposited using particles with size 0.45 μm exhibited some craters on the surface, significantly flat film surfaces were obtained. However, particles with size 0.3 μm create a slightly rough film surface, but the dielectric constant was greater than in the case involving particles with size 0.45 μm. Consequently, a suitably large particle size significantly influences the deposition rate and improvement in the surface roughness, and a uniform particle size distribution appears to contribute to an improved dielectric constant. Therefore, it is believed that the dielectric properties along with the growth characteristics can be enhanced by limiting particle size and shape.

Al₂O₃ powders with particle sizes of 0.35 μm, 0.5 μm, 1.5 μm, and 2.5 μm are deposited onto glass and Cu substrates using the aerosol deposition (AD) process. The deposition characteristics of Al₂O₃ films using those four types of Al₂O₃ powders are investigated to determine the influence of the particle size on the films. To observe detailed micro-structures of the films, the cross-section and surface morphology are observed. Then, the crystalline size and internal strain are calculated from X-ray diffraction peaks in order to confirm the hammering effect as well as the micro-strain during the AD deposition. From the above results, deposition mechanisms related to the particle size are studied. The results of this study indicate the optimal particle size and formation mechanisms for dense Al₂O₃ film with a smooth surface roughness as well as for a porous Al₂O₃ film with a rough surface roughness.

The effect of particle sizes on the aerosol deposition (AD) of Cu films is investigated in order to understand the deposition behaviors of metal powder during the AD process. The Cu coatings fabricated by using 2 μm Cu powders had a dense microstructure, a high deposition rate (1.6 ± 0.2 μm/min), and low resistance (9.42 ± 0.4 μΩ·cm) compared to that from using Cu powder with a particle size greater than 5 μm. Also, from estimating the internal micro-strain of Cu films, the Cu coatings fabricated by using 2 μm Cu particles exhibited a high micro-strain value of 3.307×10^-3. On the other hand, the strain of Cu coatings fabricated with 5 μm particles was decreased to 2.76×10^-3. These results seem to show that the impacted Cu particles are compressed and flattened by shock waves, and that their bonding is associated with the high internal micro-strain caused by plastic deformation.

Al2O3 films on silicon carbide were fabricated by Aerosol deposition with annealing temperatureat 800℃ and 1,000℃. The effect of thermal treatment on physical properties of Al2O3 thin films has beeninvestigated by XRD (X-ray diffraction), AFM (atomic force microscope), SEM (scanning electronmicroscope), and AES (auger electron spectroscopy). Also electrical properties have been investigated byKeithley 4,200 semiconductor parameter analyzer to explain the interface trapped charge density (Dit),flatband voltage (VFB) and leakage current (Io). Al2O3 films become crystallized with increasingtemperature by calculating full width at half maximum (FWHM) of diffraction peaks, also surfacemorphology is observed by topography measurement in non-contact mode AFM. Dit was 2.26×10-12eV-1.cm-2 at 800℃ annealed sample, which is the lowest value in all samples. Also the sample annealedat 800℃ has the lowest leakage current of 4.89×10-13 A.

CIGS is one of thin film solar cell and has been studied so much, because of the possibility of low price and high efficiency. Until now, co-evaporation and sputtering were typical method to prepare CIGS absorption layer, and a few company commercialized solar cell by these method. However,non-vacuum process which has been studied for long time has not been progressed, though the merit of low price. Especially, aerosol deposition method has not been reported, because it is difficult to prepare a large quantity of various CIGS powder. In this study, CIGS powder was synthesized by mechanochemical method and CIGS absorption layer was deposited by aerosol deposition method. The thickness of the CIGS layer was controlled by the number of deposition and the surface roughness of it was affected by the amount of flow gas. And, also, I-V curve of it appeared metallic property in the case of ‘as deposition’. After heat treatment in Se-rich atmosphere, the electrical property of it changed to a semiconductor. CdS and transparent conduction layer were formed by a typical method on it for solar cell. The efficiency of cell was appeared 0.19%. Though the efficiency was low because of the disharmony in the after-process, it was conformed that CIGS solar cell could be prepared by aerosol deposition.

Aerosol deposition(AD) coating that enable fabricate films at low temperature have begun to be widely researched for the integration of ceramics as well to realize high-speed deposition rates. For application of ceramic thick film by AD to display and electronic ceramic industry, fabrication of dense structure with a no cracking is required. In this study, to fabricate dense ceramic thick film, the effect of crystal phase of starting powder was investigated. For this study, amorphous and crystalline SiO2 powders were used as starting powders. Two types of SiO2 powders were deposited on glass substrate by AD. In the case of amorphous SiO2 powder, the deposited films had extremely incompact and opaque layer, irrespective of particle size. In contrast to amorphous powder, in the case of crystalline powder, porous structure layer and dense microstructure with no cracking layer were fabricated depending on the particle size. The optimized starting powder size for dense coating layer was 1∼2 μm. The transmittance of film reached a maximum of 76% at 800 nm.

Room temperature powder spray in vacuum process, so called Aerosol deposition (AD) is a room temperature (RT) process to fabricate thick and dense ceramic films, based on collision of solid ceramic particles. This technique can provide crack-free dense thin and thick films with thicknesses ranging from sub micrometer to several hundred micrometers with very fast deposition rates at RT. In addition, this technique is using solid particles to form the ceramic films at RT, thus there is few limitation of the substrate and easy to control the compositions of the films. In this article, we review the progress made in synthesis of piezoelectric thin/thick films, multi-layer structures, NTC thermistor thin/thick films, oxide electrode thin films for actuators or sensor applications by AD at Korea Institute of Materials Science (KIMS) during the last 4 years.