The monolith modules have similar structure to amorphous silicon modules that are currently used in the market. Monolith modules use a single sheet of conductive glass (FTO) where successive layers of TiO2 are formed on the substrate. Prior films deposition the glass is scribed by a laser in order to isolate one cell from the other. Direct wiring is not needed in this type of modules. It records relatively broad available area and high conversion efficiency, and enables simultaneous production of multiple cells (Wang et al., 2010). Usually, the TiO2 stripes are formed according to screen printing method. It also entails shortcomings that it must secure even efficiency of each cell since it is in serial connection mode, it may by damaged due to relatively weak surface, and it rather has low transmittance. The figure 7 appears below, illustrates the manufacturing method of a monolith module:
It concerns series connections of individual cells and consists of two opposing electrodes with inner-connections between neighbouring cells by a metal conductor. A sealing material is needed to protect the metal conductor from corrosion by iodide ions. It has wide available area to realize relatively high photoelectric conversion efficiency and enables transparent and double sided cell production. The Z-module entails shortcomings that it is difficult to match the junction for large-area cell production, it needs to reduce each cell efficiency deviation due to the series connection, and it is greatly affected by inner-connector reliability and conduction property (Sastrawan et al., 2006). The advantage of Z-type module fabrication is the high voltage output. On the other hand, the disadvantage of this
connection is the low active area and overall efficiency because of the complicated structure and the resulting high series resistance. Figure 8b illustrates a possible Z-module manufacturing process.