Method And Apparatus For Screening Combinatorial Libraries For Semiconducting Properties

Abstract

This invention discloses methods, materials, and devices for making and screening combinatorial libraries to identify semi-conducting and thermoelectric materials. The disclosed method includes preparing a combinatorial library of materials, and identifying library members that are semiconductors. The method may include determining a thermoelectric figure of merit, ZT, for each member of a second combinatorial library of materials. The method determines ZT by applying an oscillatory voltage across the library members, measuring power dissipated by library members, and calculating ZT from the power dissipated. The method may also include isolating single-phase materials of the semiconducting library members. The present invention also discloses an apparatus for discovering thermoelectric materials using combinatorial techniques. The apparatus includes a first combinatorial library of materials comprised of thin films arrayed on a substrate, and a device for identifying semiconducting members of the first combinatorial library. In addition, the apparatus may include a device for measuring ZT—a voltage source for applying an oscillatory electrical potential across members of a second combinatorial library arrayed on a substrate, and a device for measuring the resulting power dissipated by library members. The apparatus may also include a device for isolating single-phase materials of library members that were identified as semiconductors.

1 . An apparatus for discovering materials comprising: 
 a combinatorial library of materials having members arrayed on a substrate;    a voltage source for applying an oscillatory electrical potential across each of the members arrayed on the substrate; and    a device for measuring power dissipated by each of the members of the combinatorial library of materials during application of the oscillatory electrical potential.    
     
     
         2 . The apparatus of  claim 1 , wherein the members of the combinatorial library of materials are arrayed on a substrate having a lower thermal conductivity than each of the members.  
     
     
         3 . The apparatus of  claim 2 , wherein the substrate is a polyimide.  
     
     
         4 . The apparatus of  claim 1 , wherein each of the members of the combinatorial library of materials have first and second ends, the first and second ends of each of the members in contact, respectively, with first and second contacts, the first and second contacts connected to the voltage source so that the oscillatory electrical potential can be applied across each of the members simultaneously.  
     
     
         5 . The apparatus of  claim 1 , wherein the device for measuring power dissipated by each of the members of the combinatorial library of materials during application of the oscillatory electrical potential is an infrared detector.  
     
     
         6 . The apparatus of  claim 5 , wherein the infrared detector is a bolometer.  
     
     
         7 . The apparatus of  claim 5 , wherein the infrared detector is a photodiode.  
     
     
         8 . The apparatus of  claim 6 , wherein the infrared detector is a focal plane array.  
     
     
         9 . The apparatus of  claim 1 , further comprising a computer for transforming the power dissipated by each of the members of the combinatorial library of materials as a function of time to power dissipated as a function of frequency.  
     
     
         10 . The apparatus of  claim 1 , further comprising a vacuum chamber for containing the combinatorial library of materials during application of the oscillatory electrical potential.  
     
     
         11 . An apparatus for discovering materials comprising: 
 a first combinatorial library of materials;    a device for identifying semiconducting members of the first combinatorial library of materials;    a device for isolating single-phase materials of the semiconducting members of the first combinatorial library of materials;    a second combinatorial library of materials having members comprised of at least a portion of the single-phase materials;    a voltage source for applying an oscillatory electrical potential across each of the members of the second combinatorial library of materials; and    a device for measuring power dissipated by each of the members of the second combinatorial library of materials during application of the oscillatory electrical potential.    
     
     
         12 . The apparatus of  claim 11 , wherein the device for isolating single-phase materials of the semiconducting members of the first combinatorial library of materials is a differential scanning calorimeter.  
     
     
         13 . The apparatus of  claim 11 , wherein the device for isolating single-phase materials of the semiconducting members of the first combinatorial library of materials is a scanning x-ray diffraction unit.  
     
     
         14 . The apparatus of  claim 11 , wherein the device for isolating single-phase materials of the semiconducting members of the first combinatorial library of materials is an energy dispersive x-ray spectrometer.  
     
     
         15 . The apparatus of  claim 11 , wherein the device for isolating single-phase materials of the semiconducting members of the first combinatorial library of materials is a secondary ion mass spectrometer.  
     
     
         16 . The apparatus of  claim 11 , wherein the device for isolating single-phase materials of the semiconducting members of the first combinatorial library of materials is an x-ray fluorescence spectrometer.