Wide temperature range operation of GaN HEMTs for power dense energy conversion

Device characterization of a Gallium Nitride (GaN) High Electron Mobility Transistor (HEMT) from 48 K to 300 K is performed in order to assess the switch's potential performance in superconducting power systems where power densities upward of 6 MW/m³ are required. Forward and reverse channel resistance, leakage current, and threshold voltage will be measured to perform the assessment. The results will show an 81.7% and 97% reduction in channel resistance for the forward and reverse channel directions, a threshold voltage increase of 6.2%, and a leakage current which indicates no reduction in blocking voltage with temperature. Due to the thermal management system (TMS) consuming the entire volume of a 6 MW/m³ power conversion system under cryogenic conditions, an above ambient (>300 K) operation power conversion system will also be presented for comparison. The power converter will feature a high performance integrated fluid cooled semiconductor module rated for 1.3 kV and >300 A. The final selected module design will be based on the results of a trade-study that determines the optimum location of cooling channels, channel geometry, cooling fluid, and substrate and die-attach material selection.