DETERMINATION OF THE PELTIER COEFFICIENT OF GERMANIUM IN A VERTICAL BRIDGMAN-STOCKBARGER FURNACE

The Peltier effect is the fundamental mechanism that makes interface d emarcation through current pulsing possible. If a method for calculati ng the necessary current density for effective demarcation is to be de veloped, it will be necessary to know the value of the Peltier coeffic ient. This study determined experimentally the value of the Peltier co efficient for gallium-doped germanium by comparing the change in avera ge growth rates between current-on and current-off periods. Current-on and current-off layer thickness measurements were made using differen tial interference contrast microscopy and atomic force microscopy. It was found that the Joule and Thomson effects could not be neglected. P eltier coefficients calculated from the experimental data with an anal ysis that accounts for Joule, Thomson, and Peltier effects yielded an average value for the Peltier coefficient of 0.076 +/- 0.015 V.