Modeling the Spectral Luminescence Emission of Silicon Solar Cells and Wafers

A generalized expression for the theoretical description of luminescence spectra of silicon solar cells and wafers is outlined. Models of the spectral luminescence emission, which can be found in the literature, are reviewed and compared with spectrally resolved photoluminescence measurements carried out on specially prepared samples. These models describe the spectrum of samples with either two planar or two rough (lambertian reflecting) surfaces. Good qualitative agreement is shown. Moreover, we introduce a new model which is valid for samples with any configuration of planar and textured surfaces and also takes free carrier absorption into account. The accuracy of the model is experimentally confirmed by a comparison to an electroluminescence spectrum of an industrial silicon solar cell.