Hall mobility of polycrystalline silicon

Abstract

Hall mobility of polycrystalline silicon was measured in the dark and under illuminated conditions. Grain boundary potential barriers present in the dark can be eliminated with light. When the barriers are removed, the mobility between 200 and 400 K is found to vary as T⁻², which is the dependence observed in single crystals for the same order of magnitude of doping. The free‐carrier concentration of 5×10¹⁵ cm⁻³ was not affected by illumination, and the room temperature mobility in 1‐mm grain size material after barrier elimination with light was 900 cm²/V sec. A phenomological theory of Hall mobility in polycrystallllne silicon which explains these observations is presented.