Optical enhancement of solar cells

A thermodynamic limit of 4n/sup 2/approx. =50 exists for the maximum absorption increase in a randomly textured semiconductor, where n is the semiconductor index of refraction. Optically enhanced solar cells do not achieve this large absorption increase due to parasitic optical absorption by the electrode structure and, scattering properties of surface textures. In this article the authors present a model of absorption enhancement in solar cells which relates independent optical measurements of parasitic absorption and texture performance to measured collection efficiency spectra. Using this model they define limits for short circuit current increases produced by enhancement.