Investigation of modified p-n junctions in crystalline silicon on glass solar cells

In this paper various methods for studying p-n junctions in thin film solar cells are applied with the aim to localize and investigate defects on a microscopic scale. Different electron and ion beam characterization methods are introduced to determine the p-n junction position using two different examples from crystalline silicon on glass thin film technology. In a first example, planview and cross section electron beam induced current measurements revealed that oxygen rich columnar growth at textured substrates strongly disturbs the p-n junction. In a second example, diffusion from glass substrate is identified by ToF-SIMS to influence the electrical and structural characteristics of the thin Si layer resulting in a modified p-n junction. A model describing the formation of both defect structures is introduced.