Inverse Nottingham Effects Cooling of Semiconductors with Resonant Tunneling
Final rept. 15 Apr 1999-15 Oct 2003
NORTH CAROLINA UNIV AT CHARLOTTE
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Heat removal by Inverse Nottingham Effect INE is a new concept utilizing hot electrons emitted from the semiconductor surface into the vacuum via field emission. The replenishment of hot electrons in the semiconductor as a result of reestablishment of thermal equilibrium constitutes cooling. To avoid heating from current crowding, tips are replaced by a double barrier resonant tunneling structure DBRT at the surface of a semiconductor to allow efficient field emission via resonant tunneling. We recognized that the most important Step is to achieve high emission from the semiconductor into the vacuum. A double barrier structure with Ga.5 AL.5 N as barrier material with GaN well is designed and chosen for the desired high emission. A CVD structure grown by Prof. A. Khan, on SiC substrate, taken to University Lyon to be measured by Prof. Binh, resulted in a breakthrough for field emission, with a threshold field of 50 V microm, with stable FE current densities of 3xlO2Acm2. V. Seniet, V.Binh, J, Zbang, J.Yang, A.Khan and R. Tsu, APL 84, 1937, 2004. Although we have not succeeded in cooling due to problems created by radiation back from the anode, this breakthrough in field emission is an important by product of our research which can benefit various field, principally vacuum electronics, such as cold cathode for traveling wave tubes. In fact, the measured exceeded the calculated because we did not realize that the bulk of the high emission came from the effective lowering of the work function at the surface created by space charge in the quantum state.
- Solid State Physics
- Quantum Theory and Relativity