Optimization of transparent conductor-embedding front electrodes for efficient light management

An optically and electrically optimum designed front electrode is reported by using a transparent conductive oxide (TCO) film integration. A substantial enhancement of light absorption was achieved by reduction of silver (Ag) grid shading losses while holding a similar series resistance. This obviously improves the solar cell efficiency with a significant reduction in the use of Ag shading area by one fourth. Due to the optical and electrical excellent indium-tin-oxide (ITO), the TCO benefits to widen the light transparent surface and spontaneously works as an anti-reflection coating layer.We have demonstrated that a trade-off between the optical and the electrical aspects should be considered to transfer the optical benefit by ITO supporting transparent electrode to the practical electrical advantage of current enhancement. Transmission line method was applied to profile the variation of contact resistances and specific contact resistance for optimum design of ITO-integrated front electrodes.

► An optimum transparent conductor-embedding front electrode was designed.
► The enhanced light absorption was achieved by reduction of Ag grid shading losses.
► Possible amount of Ag reduction is 75%.
► A trade-off between optical and electrical aspects should be considered.