Chapter 5
Crystalline Silicon Solar Cells:
Homojunction Cells
Sylvère Leu and Detlef Sontag
Abstract In Chap. 3 we learned about the typical functioning of a semiconductor
under the influence of light: Light can generate an electric current; this happens if an
electron absorbs energy from the light and detaches itself from its atom—it becomes
thereby a free charge carrier, which contributes to power generation. This is called
the “photovoltaic effect”. In the following, our aim will be to understand the use of
the photovoltaic effect to a greater depth, so as to be able to design and fabricate
solar cells with higher efficiencies. In order to better understand the cell concept, it is
important to understand the preceding crystallization process and the wafering process. Thereafter we will discuss the development of the basic homojunction Al-BSF
(Aluminium Back Surface Field) solar cell. The further development of the Al-BSF
cell takes us to the PERC cell (Passivated Emitter Rear Cell). We will look at these
cell designs in detail. Based on the potential for improvement of the PERC cell we
will explain the cell concept of the PERT cell (Passivated Emitter and Rear Totally
Diffused cell) and the different architectures of advanced cell designs such as TOPCon cell (Tunnel Oxide Passivation Contact). To conclude, we will briefly discuss
the IBCs (Interdigitated Back Solar Cells), which achieve the highest efficiency so
far for single-junction silicon solar cells.
5.1 Production of Silicon Wafers and Solar Cells
5.1.1 Production of Silicon Ingots
Crystalline solar cells used for large-scale terrestrial applications consist almost
exclusively of silicon as base material. There are good reasons for this:
S. Leu · D. Sontag (B)
Meyer Burger Technology A.G, Gwatt, Switzerland
e-mail: dsontag@web.de
S. Leu
e-mail: sylvere.leu@ciptec.ch
© Springer Nature Switzerland AG 2020
A. Shah (ed.), Solar Cells and Modules, Springer Series in Materials Science 301,
https://doi.org/10.1007/978-3-030-46487-5_5
97
Crystalline Silicon Solar Cells:
Homojunction Cells
Sylvère Leu and Detlef Sontag
Abstract In Chap. 3 we learned about the typical functioning of a semiconductor
under the influence of light: Light can generate an electric current; this happens if an
electron absorbs energy from the light and detaches itself from its atom—it becomes
thereby a free charge carrier, which contributes to power generation. This is called
the “photovoltaic effect”. In the following, our aim will be to understand the use of
the photovoltaic effect to a greater depth, so as to be able to design and fabricate
solar cells with higher efficiencies. In order to better understand the cell concept, it is
important to understand the preceding crystallization process and the wafering process. Thereafter we will discuss the development of the basic homojunction Al-BSF
(Aluminium Back Surface Field) solar cell. The further development of the Al-BSF
cell takes us to the PERC cell (Passivated Emitter Rear Cell). We will look at these
cell designs in detail. Based on the potential for improvement of the PERC cell we
will explain the cell concept of the PERT cell (Passivated Emitter and Rear Totally
Diffused cell) and the different architectures of advanced cell designs such as TOPCon cell (Tunnel Oxide Passivation Contact). To conclude, we will briefly discuss
the IBCs (Interdigitated Back Solar Cells), which achieve the highest efficiency so
far for single-junction silicon solar cells.
5.1 Production of Silicon Wafers and Solar Cells
5.1.1 Production of Silicon Ingots
Crystalline solar cells used for large-scale terrestrial applications consist almost
exclusively of silicon as base material. There are good reasons for this:
S. Leu · D. Sontag (B)
Meyer Burger Technology A.G, Gwatt, Switzerland
e-mail: dsontag@web.de
S. Leu
e-mail: sylvere.leu@ciptec.ch
© Springer Nature Switzerland AG 2020
A. Shah (ed.), Solar Cells and Modules, Springer Series in Materials Science 301,
https://doi.org/10.1007/978-3-030-46487-5_5
97