Kirchhoff's generalised law applied to amorphous silicon/crystalline silicon heterostructures

The electro and photoluminescence spectra of amorphous silicon/crystalline silicon heterostructures and solar cells are determined by emission from the crystalline silicon layer and are computed with Kirchhoff's generalised law. The interface defect density strongly influences the luminescence yield, which may be used to monitor interface quality. Based on a comparison between numerical and analytically determined spectra, the temperature dependence of experimental electroluminescence and photoluminescence spectra of these silicon heterostructures is analysed. We find a clear indication of the validity of Kirchhoff's generalised law for luminescence emission from these silicon structures and conclude that it can be applied between 112 and 363K without further modification to account for the indirect nature of the optical transitions in crystalline silicon.