**3. Conclusions**

Process flows of conventional silicon solar cell, Ni/Cu plating for silicon solar cells, passivated emitter rear contact solar cells, and interdigitated back contact solar cells were discussed. Influences of process parameters in electrical parameters were analyzed. Though the contact formed by lithography, sputtering, etc. is reliable and resulting in good energy conversion efficiency, however, it is expensive due to the vacuum evaporation and single wafer type process. In this context, screen printed contacts are consistent in reliable and providing the best approach in production industry. Screen printing-based metallization is one of the key and crucial processes in silicon solar cell fabrication process which was discussed by interpreting the paste rheology, screen, and printing parameters. The screen printing paste used for contacting the solar cells is the other expensive element after the silicon wafer, and thus it is important to find an alternate technique for silver paste-based printing mechanism. Researchers arrived at a Ni/Cu plating technique for contact mechanism, and the technique has proved its capability in manufacturing industry as well. However, advanced structures such as PERC and IBC are using either screen printing or evaporation technique for making contacts. By seeing current scenario of metallization in different types of solar cells, it has been concluded that screen printing will continue to be an important and reliable metallization technique. The current efficiency status of different silicon solar cell technologies is depicted in **Table 4**.


#### **Table 4.**

*Current efficiency trend of different technology solar cells [36, 77, 99].*
