Black Silicon Photovoltaics

The name "black silicon" refers to all randomly structured silicon interfaces with lateral feature sizes in the submicron range and aspect ratios (structure height/lateral feature size) larger than one. There are a variety of possibilities to achieve a black silicon structure at the silicon interface. From a historical point of view the development is a result of integrated circuit technologies, especially the structuring of silicon by plasma and dry etching processes. Reactive ion etching (RIE) processes seem to be promising candidates for the structuring of solar cells. The structure evolution of black silicon under repeated pulsed laser irradiation can be understood as an interference effect. The light trapping properties of the investigated black silicon structures depend strongly on the feature size of the structures. As a result of the excellent light trapping, high short-circuit currents are a common property of almost all cell concepts.