It causes a color difference on the solar panels and affects the effectiveness of the panels.
Belinus has developed an ultra black solar cell that absorbs 99.7% of available sunlight using assivated emitter and rear contact (PERC) solar cell technology. This is a huge step forward from the anti-reflective coatings currently applied to solar panels. Belinus has named this particular set of solar cells BE.
The tint of the surface of a silicon wafer, after micro-pore etching, is called "ultra black solar". Etching takes place in a liquid solution that is brought to room temperature within minutes. The pores increase the amount of light absorbed by the cell. The cells appear completely dark, while almost all the light is absorbed.
It is recommended that solar cells have as little reflectivity as possible, because sunlight that is reflected instead of absorbed is "lost". A well-polished silicon wafer surface has a reflectivity of about 40%, giving it a shiny appearance. When the standard anti-reflective coating is applied, the average reflectivity drops to about 6%, giving the cells their characteristic dark blue colour.
The reflection coefficient is the percentage of light that falls on a surface and is reflected. A reflection coefficient of 0.3% means that only 0.3% of the incident light is reflected by the surface of the solar cell, while 99.7% of the incident light is absorbed and converted into electricity.
A reduction of the reflection coefficient by a factor of 10 will allow up to 3% more usable light into the cell, effectively increasing the efficiency of that cell by the same percentage. For example, a cell of 20.4% efficiency becomes a cell of 20.9% efficiency.
However, there are other advantages to using black silicon. A panel composed of black solar cells will generate considerably more energy than a panel composed of cells with (the industry standard) anti-reflective coating. This is primarily because they reflect less light. But also because they perform better when the sun is at a certain angle in the morning and afternoon. They also perform better than normal solar cell panels on cloudy days.
The ability of Belinus' liquid phase deposition (LPD) technique to passivate black solar cells has been the missing link, up until now. This is what enables black silicon to reach its full potential.
The ultra black solar cells are aesthetically pleasing and provide excellent performance and efficiency. The solar cells have a smooth black colour, making it a fantastic option for roofs. Interesting for people who like living in style and want to show it off.
The Belinus modules with Ultra Black solar cell technology maximise the system's performance, bringing high-efficiency PV modules with an attractive appearance onto the European market.
Belinus specialises in the research, development and production of innovative ultra-efficient ultra-black solar double glazing, home battery and BIPV solutions.