Dynamic deposition system for fabrication of amorphous/crystalline silicon heterojunction solar cells combining linear hot-wire and plasma enhanced chemical vapor deposition methods.

In this work an integration of two in-line deposition methods consisting of a linear hot-wire (HW) and very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) into a single in-line system for the fabrication process of highly efficient heterojunction solar cells was demonstrated. Using this continuous deposition methods, which are also well suited for roll-to-roll production, a high productivity can be achieved. In principle, the up-scaling of the electrode width is possible and no severe deterioration of the uniformity of the deposited layers is expected. With the linear configuration the homogeneity of the layer deposition has to be ensured in only one dimension (perpendicular to the movement direction of the substrate). The homogeneity in the second dimension is realized by the movement of the substrate at constant speed, thus the homogeneous deposition even on large area substrates is possible. In this work the individual steps for development of the passivation process using different in-line deposition methods were investigated. The results show that dynamic HW- and VH-PECVD technologies enables fabrication of the layers with high deposition rates and high passivation properties (carrier lifetimes > 13 ms) as well as highly efficient solar cells (efficiency > 22%).