Mechanism of performance limitations in heavily doped silicon devices

Abstract

Proposed mechanisms for the observed performance limitations in heavily doped silicon transistors and solar cells are reexamined in detail. The physical‐defect mechanism is ruled out by the uniformly negative results of new measurements of defects by x‐ray topography and deep‐level spectroscopy. Extensive analysis of the band‐gap‐narrowing mechanism discloses a number of flaws that rule it out also. As an alternative to these models, it is proposed that Auger processes in heavily doped regions of the devices are the dominant source of the observed limitations. An order‐of‐magnitude calculation for the solar‐cell case leads to good agreement with the observed maximum open‐circuit voltage.