HIGH TEMPERATURE THERMALLY STABLE MULTI-LAYER QUANTUM WELL FILMS

AN ATTEMPT WILL BE MADE TO FABRICATE MULTI-LAYER QUANTUM WELL FILMS (ML-QWFS) THAT SHOULD HAVE AN EXCEPTIONALLY HIGH FIGURE OF MERIT (Z) FROM MATERIALS THAT EXHIBIT VERY LOW DIFFUSION RATES. SUCH MATERIALS PREVENT THE QUANTUM WELL AND BARRIER MATERIALS FROM INTERDIFFUSING, THEREBY DEGRADING THE MULTILAYER NANOSTRUCTURE RESPONSIBLE FOR THE IMPROVED PERFORMANCE. THE IMPROVED PERFORMANCE BELIEVED TO BE POSSIBLE WITH SUCH MATERIALS IS DUE TO THE CONFINED MOTION OF THE CHARGE CARRIERS AND THE TWO DIMENSIONAL QUANTUM WELL WHICH IS IN CONTRAST TO THEIR THREE DIMENSIONAL MOTION IN COMPARABLE BULK MATERIALS. THE LAYERING MAY ALSO DECREASE THE THERMAL CONDUCTIVITY. THE GOAL OF THIS EFFORT IS TO DEVELOP ML-QWFS THAT CAN OPERATE UP TO 1100 DEGREES CENTIGRADE FOR >10 YEARS. PARAMETERS SUCH AS LAYER THICKNESS, RESIDUAL STRAIN IN THE LAYERS, AND TYPE OF CRYSTAL STRUCTURE WILL ALL BE CONSIDERED IN THE SELECTION OF THE QUANTUM WELL AND BARRIER MATERIALS. DURING PHASE I VARIOUS BORIDE ALLOYS WILL BE ALTERNATELY DEPOSITED INTO QUANTUM LAYERS AND THEIR THERMOELECTRIC PROPERTIES CHARACTERIZED.