The etching process can be physical and/or chemical, wet or dry, and isotropic or anisotropic. All these etch process variations can be used during solar cell processing. Figure 1: Etching processes divided according to their physical, chemical, or combined (physical and chemical) nature.
Wet etching can be used to remove residual saw damage, to texture, to polish, to clean material and/or to reveal defects in the wafers. There are three major wet etching types , see Fig. 3:
Plasma etching enables an anisotropic mesa isolation without micro fractures. These two characteristics are obtained with the combination of the plasma ion-bombardment and chemical etching, resulting in excellent cell performance. Residual plasma damage removal by wet etching has also been reported previously on GaN .
Plasma etching offers an interesting pathway for multijunction solar cell miniaturization . Despite the fact that this study is focussed on triple junction solar cells, all mesa isolation methods could be relevant for other III–V-based devices such as four, five or six junction solar cells, phototransducers and light-emitting diodes.
Reactive ion etching is used to edge isolate. During wet etching processes, the solid is immersed in a chemical solution (which can be either acidic or alkaline) and material is removed by dissolution. Wet etching can be used to remove residual saw damage, to texture, to polish, to clean material and/or to reveal defects in the wafers.
& FacilitiesMaterialsCellAbStrActWet processing can be a very high performing and ost-effective manufacturing process. It is therefore extensively used in Si solar cell fabrication for saw damage removal, surface texturing, cleaning, etching of paras