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Texturing by reactive ion etching (RIE) is demonstrated as an attractive technical solution for lowering of reflectance of multicrystalline silicon solar cells. A suitable sequence of processes is developed to combine the advantage of reactive ion etching with “natural lithography” based on colloidal masks. The RIE single-wafer texturisation is driven to an industrial applicable batch process by plasma etching with a gain in efficiency of 0.3% absolute. [Copyright &y& Elsevier]

Texturing of multicrystalline silicon solar cells by reactive ion etching (RIE) is demonstrated as an attractive solution for lowering of reflectance. A suitable sequence of processes is developed to exploit the advantage of RIE in combination with “natural lithography” based on colloidal masks. A homogeneous particle coverage on 4 in. monocrystalline wafers and on 100×100 mm2 multicrystalline wafers (Baysix) has been achieved. Finally, texture is obtained by RIE patterning. Data of optical properties are presented. A significant lowering of the reflection of textured wafers compared to untexture is achieved for all states of solar cell production. [Copyright &y& Elsevier]

In technical applications of polycrystalline metals, the grain structure and role of grain boundaries are of great importance. Electron back scattering diffraction (EBSD) identifies the surface orientation of grains. In combination with microelectrochemical techniques, single crystal experiments can be carried out on polycrystalline metals. Application of AFM (atomic force microscopy), LFM (lateral force microscopy) and dF/ds (force microscopy) can provide complementary information in the nanometre range, e.g. on grain boundaries. As an example, the etching and passivation of Ti (hcp) has been investigated. First, a variety of technical samples from different companies were analysed with respect to grain size, orientation, and twins formation. AFM showed different roughnesses on grains (e.g. (0001) >(xxx0)), while dF/ds demonstrated the greater hardness of films on (0001) compared with (xxx0). Grain boundaries between grains of the same and different orientations must be distinguished. In iron the topography of grain boundaries (steps, hills, trenches) shows a clear dependence on the polishing procedure and on the orientation of neighbouring grains. (100) orientated grains always show the fastest metal removal during both chemical and electrochemical polishing. These effects can be correlated with different surface packing densities of the relevant crystal faces. [ABSTRACT FROM AUTHOR]