High-quality epitaxial AlN films were deposited on sapphire substrates at low growth temperature using a helicon sputtering system. SAW filters fabricated on the AlN films exhibited excellent characteristics, with center frequency of 354.2 MHz, which corresponds to a phase velocity of 5667 m/s. An oscillator fabricated using AlN-based SAW devices is presented and applied to deep-UV light detection. A frequency downshift of about 43 KHz was observed when the surface of SAW device was illuminated by a UV source with dominant wavelength of around 200 nm. The results indicate the feasibility of developing remote sensors for deep-UV measurement using AlN-based SAW oscillators.
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http://dx.doi.org/10.1109/TUFFC.2011.1997 | DOI Listing |
Micromachines (Basel)
December 2024
School of Integrated Circuit, Southeast University, Nanjing 210096, China.
Aluminum nitride (AlN) with a wide band gap (approximately 6.2 eV) has attractive characteristics, including high thermal conductivity, a high dielectric constant, and good insulating properties, which are suitable for the field of resistive random access memory. AlN thin films were deposited on ITO substrate using the radio-frequency magnetron sputtering technique.
View Article and Find Full Text PDFLangmuir
January 2025
Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague 8, Czech Republic.
Black aluminum is a material characterized by high surface porosity due to columnar growth and exhibits unique optical properties that make it attractive for applications such as light trapping, infrared detection, and passive thermal radiation cooling. In this study, we correlate the structural and optical properties of black aluminum by comparing it with conventional reflective aluminum layers. These layers of varying thicknesses were deposited on fused silica substrates, and their optical properties were analyzed.
View Article and Find Full Text PDFMicrosyst Nanoeng
December 2024
Department of Mechanical Engineering, University of California, Berkeley, CA, 94720, USA.
This work presents air-coupled piezoelectric micromachined ultrasonic transducers (pMUTs) with high sound pressure level (SPL) under low-driving voltages by utilizing sputtered potassium sodium niobate KNaNbO (KNN) films. A prototype single KNN pMUT has been tested to show a resonant frequency at 106.3 kHz under 4 V with outstanding characteristics: (1) a large vibration amplitude of 3.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Boron (B)-substituted wurtzite AlN (AlBN) is a recently discovered wurtzite ferroelectric material that offers several advantages over ferroelectric HfZrO and PbZrTiO. Such benefits include a relatively low growth temperature as well as a thermally stable, and thickness-stable ferroelectric polarization; these factors are promising for the development of ferroelectric nonvolatile random-access memory (FeRAM) that are CMOS-compatible, scalable, and reliable for storing data in harsh environments. However, wurtzite ferroelectric materials may undergo exacerbated self-heating upon polarization switching relative to other ferroelectric materials; the larger energy loss is anticipated due to the higher coercive field and remanent polarization.
View Article and Find Full Text PDFMolecules
November 2024
Guangxi Key Laboratory of Calcium Carbonate Resources Comprehensive Utilization, College of Materials and Chemical Engineering, Hezhou University, Hezhou 542899, China.
AlN, with its ultra-wide bandgap, is highly attractive for modern applications in deep ultraviolet light-emitting diodes and electronic devices. In this study, the surface and cross-sectional properties of AlN films grown on flat and nano-patterned sapphire substrates are characterized by a variety of techniques, including photoluminescence spectroscopy, high-resolution X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and Raman spectroscopy. The results indicate that different sapphire substrates have minimal impact on the photoluminescence spectrum of the epitaxial films.
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