Coloured PV modules are considered ideal for facade applications, as they are more visible than rooftops. However, their widespread application has been held back by the lack of a PV colourisation technology that has a low impact on power conversion efficiency (PCE) and is simultaneously mass-producible at a low cost.

To address this challenge, researchers at Shanghai Jiao Tong University have created solar panels that take on colourful hues while producing energy nearly as efficiently as traditional ones. They implemented a colorization strategy based on photonic glass, which was made of a thin, disorderly layer of dielectric microscopic zinc sulfide spheres.

By a fast spray-coating process, they showed that the photonic glass layer could be easily deposited on silicon solar cells, enabling them to have structural colours. Through varying microsphere sizes, solar cells with different colours were achieved, showing low PCE loss compared to normal black cells.

Using this approach, the researchers created solar panels that took on blue, green, and purple hues while only dropping the efficiency of power generation from 22.6% to 21.5%. Moreover, the long-term stability was subsequently verified by aging tests including an outdoor exposure for 10 days and a damp-heat test for 1000 h and the mass producibility is demonstrated by presenting a coloured PV panel with an output power over 108 W.

The researchers now plan to explore ways to make the colours more saturated, as well as methods to achieve a wider range of colours. They reported their findings in High-Efficiency, Mass-Producible, and Coloured Solar Photovoltaics Enabled by Self-Assembled Photonic Glass which was recently published in ACS Publications.