Recombination mechanisms in amorphous silicon/crystalline silicon heterojunction solar cells

Abstract

This article investigates limitations to the open circuit voltage of n-type amorphous silicon/p-type crystalline silicon heterojunction solar cells. The analysis of quantum efficiency and temperature dependent current/voltage characteristics identifies the dominant recombination mechanism. Depending on the electronic quality of the crystalline silicon absorber, either recombination in the neutral bulk or recombination in the space charge region prevails; recombination at the heterointerface is not relevant. Although interface recombination does not limit the open circuit voltage, recombination of photogenerated charge carriers at the heterointerface or in the amorphous silicon emitter diminishes the short circuit current of the solar cells.