Realization of Conductive Wells for Rear Side Electrical Contact of Integrated Solar Cell

Abstract The so-called integrated solar cell (i-Cell) consists of several small area sub-cells manufactured by bonding monocrystalline Si (mono-Si) thin foils (20-60 μm) ontocost effective insulating substrates on which local conductive wells have been previously integrated. In this paper, we report on the realization of deep recrystallized conductive wells acting as the rear side electrical contact of each sub-cell. These conductive wells have been produced by screen-printing of a thick aluminum (Al) layer followed by a fast-firing process for the formation of the back electrode of each sub-cell. The i-Cell delivers a high voltage and a low current, which reduces the resistive losses in the interconnections of i-cells and modules. The influence of firing temperature profile on the depths and electrical properties of conductive wells are investigated. The feasibility of i-Cell realized on these deep recrystallized conductive wells has been demonstrated. The preliminary results, obtained from 156x156 mm 2 i-Cell on which four sub-cells are connected in series, show an efficiency over 16%, with a short circuit current of 2.1 A and an open circuit voltage of 2.5 V.