Solar energy can only succeed if the technology of solar cells is constantly improved. This guarantees a future-oriented, fast growing solar industry and the consolidation of solar energy’s pole position as the cheapest electricity generation technology. The leading technology, with a market share of ca. 95 percent, are currently monocrystalline silicon-based solar cells (thin-film modules, in contrast, have a market share of ca. five percent).
At regular intervals, new technologies that make solar cells even more efficient become established in the market. For a long time, Passivated Emitter and Rear Cells (PERC) dominated the market, but these have recently been replaced by n-type cells TOPCon, heterojunction (HJT) and IBC. According to a study by the German Mechanical Engineering Industry Association (VDMA), the projected market share of n-type cells was estimated at around 50 percent in 2024, that of PERCs just around 40 percent.
At almost 80 percent, the lion’s share of n-type cells are TOPCon cells. TOPCon stands for Tunnel Oxide Passivated Contact. The cells have an ultra-thin silicon oxide (SiOx) layer, are more efficient, less prone to degradation, and still effective at low levels of sunlight. They also have an augmented bifaciality, which is the ability to capture light on both the front and back of a PV module. Monocrystalline TOPCon n-type cells currently achieve up to 26.89 percent efficiency in the laboratory. The top efficiency of simple silicon-based solar cells is around 29 percent.
Silicon-based solar cells have been gradually improved over the last 20 years. Their efficiency has been increased through enhanced silicon surface characteristics, amongst other things. Wafer production has also seen considerable advancements recently: Their thickness has been reduced and the material loss during sawing (kerf loss) has been cut down dramatically. Industry and research institutions are now working on further saving on important and expensive materials used in silicon-based solar cells, such as silver. This will further improve the efficiency of silicon-based solar cells in the future while cutting the cost of PV modules.