Scientists Develop Paint That Can Absorb Solar Energy

It appears there is more to paint than aesthetics. Researchers have developed what appears to be photovoltaic paint, as in paint that absorbs heat and converts it to electricity. This can pave way to "paint-on solar cells" that can capture the sun's energy. 

The idea can utilize the heat of the roof and walls of buildings, especially in the summer. Since summer temperatures increase to at least 50-degrees Celsius, huge amounts of wasted heat can be converted into electrical energy. 

Jae Sung Son, a coauthor of the study, told Phys.org that the paint can especially be used in large-scale heat source surfaces such as vessels, cars and buildings. 

However, it seems the thermoelectric paint looks very different from conventional thermoelectric materials. These are normally shaped like flat, rigid chips and are attached to irregularly-shaped objects that emit wasted heat such as power plants and refrigerators. However, the incomplete contact between the surfaces still results in heat loss, thus decreasing its efficiency.

Sung Son, from the Unsol National Institute of Science and Technology, along with Sung Hoon Park and peers from the Korea Institute of Science and Technology and the Korea Electrotechnology Research Institute have tried addressing this issue. They created a thermoelectric paint that can easily attach to surfaces of any shape. 

The paint contains bismuth telluride, which is a common thermoelectric particle used in devices. Molecular sintering aids will cause the thermoelectric particles to combine, thus increasing its density along with energy conversion efficiency. Upon trial, sintering paint for 10-minutes at 450-degrees Celsius saw it form a uniform film of about 50 micrometers thick.

It also exhibited a high output power density, with values competitive and even better than all thermoelectric materials and ink-and-paste-based materials. 

Given this, the researchers are hoping that the paint could be used as wearable thermoelectric harvesters. According to Phys.org It may even be used in 3D-printed electronics, among others.