Reformulation of solar cell physics to facilitate experimental separation of recombination pathways

Abstract

Experimentally identifying the spatial distribution of recombination in a solar cell is challenging, with only semi-quantitative information available from conventional characterization techniques. We develop a formulation of solar cell physics, based upon well-justified analytic approximations, to quantitatively extract information about recombination in different cell regions. We derive the dependence of VOC on light-intensity, temperature, and strength of recombination in the space-charge, quasi-neutral, and interface regions. Expanding the scope and utility of commonly used characterization techniques, we apply this formulation to evaluate the spatial distribution of recombination in exemplary crystalline silicon heterojunction and polycrystalline Cu(In,Ga)Se2 solar cells.