Determination of the Emitter Saturation Current Density of Silicon Solar Cells Using Photoluminescence and Quantum Efficiency Analysis

Abstract

We determine the emitter saturation current density J0e of silicon solar cells using a combined approach of photoluminescence (PL) and quantum efficiency (QE) measurements. We prove that the ratio of two PL measurements obtained under open circuit and short circuit conditions yields the saturation current density J0. We obtain the saturation current density contribution of the base J0b from quantum efficiency measurements. The difference between the total saturation current density J0 and J0b yields the emitter saturation current density. This analysis is applied to both, a high-efficiency solar cell as well as to a standard industrial solar cell. The benefit of using photoluminescence is a possible spatially resolved application if combining camera-based PL measurements with mappings of the effective diffusion length.