Yellow-green is the most efficient photovoltaic colour, whereas highly saturated blue, red and purple colours produce the lowest efficiencies, when compared at equal brightness.
Does solar cell colour affect power conversion efficiency?
Prior research by Halme & Mäkinen 18 has identified the interdependence of solar cell colour and efficiency, established the most efficient way (requiring the fewest reflected photons) to produce colour for solar cells, and determined the theoretical power conversion efficiency (PCE) limits for opaque coloured solar cells.
How does colour affect a multi-junction solar cell PCE?
• For ideal solar cells and colour formation, colour affects the multi-junction solar cell PCE similarly to single-junction solar cells: higher colour lightness lowers efficiency, and among equally light colours, yellow-greens produce the highest PCE.
In most cases, except for colours with very high relative luminance Y ≳ 0.85 ( i.e. colours which are closer to white), a two-junction coloured cell has a higher limiting efficiency than a black single-junction cell, showing the potential of coloured multi-junction cells for applications where the aesthetics of solar panels play an important role.
Halme & Mäkinen showed that for SJSCs, the solar cell colour is optimally produced by one or two rectangular reflectance peaks in the visible range and that the peak positions and the solar cell bandgap energies can be optimized separately.
Do colored filters affect solar cells' output under real climatic conditions?
Aesthetic solution of photovoltaic integrated into building overview using solar cells covered with colored filters were investigated. Low-cost colored filters with 80% optical transmissivity in the range of 300–1200 nm wavelength bands are used. The colored filter's impact on the solar cells' output under real climatic conditions was identified.
Are coloured multi-junction solar cells sustainable?
However, to maximize power output from limited areas and use resources in the most sustainable way possible, keeping efficiency high is critical; coloured multi-junction solar cells, which can reach higher power conversion efficiencies than single-junction devices, thus become a technology platform of interest.