The glass layers of photovoltaic panels are made of sophisticated, resistant materials such as silica glass or transparent wood. But these materials have their limits: silica glass is fragile, and its manufacturing process generates CO2 emissions, while wood is not only flammable, but is also facing a worldwide shortage, particularly in China.

To remedy this situation and find a more sustainable, high-performance raw material, scientists at the Central South University of Forestry and Technology (Changsha, China) came up with the idea of using bamboo to make a new form of glass.

“Bamboo, often referred to as ‘the second forest,’ boasts a fast growth and regeneration rate, allowing it to reach maturity and be utilised as a building material within four to seven years of growth,” explains study co-author, Caichao Wan, quoted in a news release.

Bamboo also has a chemical composition close to that of wood, with high porosity and permeability.

“This characteristic suggests the potential use of bamboo in the production of transparent composite materials,” explains Yadong Yang, a PhD student in Wan’s lab and lead study author.

The bamboo was treated by a vacuum impregnation method, using an inorganic liquid sodium silicate. Then, a hydrophobic treatment is applied to the intermediate product.

The scientists report that this process gives rise to an innovative transparent material that “features a three-layered flame-retardant barrier, effectively reducing heat release, slowing flame spread, and restraining the emission of combustible volatiles, toxic smoke, and CO2.”

Transparent bamboo also has a high potential for light transmission, which could improve energy conversion efficiency by 15.29%, argue the researchers, who are encouraging large-scale production.

The results of this research are published in the journal Research.