Research activities of Koung-An Chao in 2002
The Lund Partner is corrently working on three projects
within the scope of the Network activities. The first one
is in the area of solid state power generation and cooling.
These two processes are reversal to each other, so let us
describe our work for cooling. In conventional approach,
the heat removal is via contact to reservoir, which is very
slow. Our breakthrough is to use both electrons and holes
to carry the heat from opposite ends to the center, where
they recombine and emit the heat in the form of light. We
call this optothermionic process. Since we published our
work, there has been much response from industries.
The second project is spin polarized transport in III-V
semiconductor heterostructures. Our spintronic system
is "All semiconductor", which has semiconductor injector,
semiconductor barrier, and semiconductor transport
channel. This novel system does not include any magnetic
element, and its operation is based on the strong spin-orbit
interaction in III-V compounds. Consequently, when the
device operates at room temperature, it still has about
10 percents spin polarization.
The third project is impurity level structure in modulation
doped semicnductor heterostructures. An ab-initia scheme
of calculation is proposed to derive all impurity-related
energy levels as well as their life times. The results of
this calculation point out a new way to construct Si-based
THz lasers using only conduction electrons.