We are working on earth-conscious materials and devices for future.

|Semiconductor Devices and Process

(1) Si/3C-SiC/Nano-crystal diamond(NCD) film devices
   For future power devices we are working on Si substrate base SiC and NCD power devices.
It is ideal to use inexpensive Si substrates rather than expensive SiC or Diamond substrates.
  We are trying to fabricate SiC buffer layer on a Si sustrate. Then depositing NCD with microwave plasma deposition.
(2) Novel paste materials for solar cell fabrication 
   We are working on novel paste materials for future solar cell for cost reduction.  There are many know-how that are not able to disclose here.

(3) Ion beam surface modification

   We are working on surface modification using a lage scale ion beam tool.  This can be used for surface cleaning or nano structure modification. 

Ultrasonic Hydrogen Sensor

For a hydrogen energy society such as using fuel cells, it is necessary to use a small and low cost hydrogen sensor. We study a hydrogen sensor using ultrasonic for practical use (right picture). 
We are also challenging in a new method of measurements as an application of the ultrasonic. [1], [2]
 We also succeeded in measuring gas concentration in side the pipe from exterior of the pipe without making any hole to extract the gas for the first time. It is not so difficult to measure in a PVC pipe, however, it is necessary to suppress the  noise sound for metallic pipe using sound absorbing material. [3], [4]

|Hydrogen gegeration and


We are trying to generate or storage hydrogen using waist materials.  Hydrogen is necessary for future hydrogen society and als human health.

- Electrical contacts to nanocrystalline diamond films studied at high temperatures, N. Shimoda, Y. Kato and K. Teii, J. Appl. Phys. 120, pp.235706-1 (2016).

-  Rectification properties of n-type nanocrystalline diamond heterojunctions to p-type silicon crbide at high temperatures, M. Goto, R. Amano, N. shimoda, Y. Kato, and K. Teii, Appl. Phys. Lett. 104, pp.153113-1 - 153113-3 (2014).

- Formation of epitaxial 3C-SiC layers by microwave plasma-assisted carbonization, Y. Kato, M. Goto, R. Sato, K. Yamada, A. Koga, K. Teii, C. Srey, and S. Tanaka, Surface& Coatings Technology 206, 990-993 (2011).

[1] Y. Kato, "A Hydrogen Sensor using Ultrasonic", Proc. of Symposium on Ultrasonic Electronics, Vol. 29 (2008), pp.215-216. 
 [2] M. Sonoyama, H. Fujita, and Y. Kato,  “Application of ultrasonic to a hydrogen sensor,”  2010 IEEE SENSORS, pp. 2141–2144.
[3] M. Taskin, Y. Kato, “Instant Gas Concentration Measurement Using Ultrasound from Exterior of a Pipe”, IEEE Sens Jvol. 19, pp. 4017-4024, 2019.
[4] M. Taskin, G. Utsumi, and Y. Kato, “Observation of Ultrasonic Signal and Measurement of H2 Concentration from the Exterior of a Metal Pipe,” Int. J. Hydrogen Energy, 2019. (Submitted).