Scientists working with quantum dot technology have developed a two-pane solar glass, which can generate efficiency, as well as provide insulation and shading. The glass incorporates two different quantum dot layers, tuned to absorb different parts of the solar light spectrum.
This tuning, known as ‘solar-spectrum splitting’, allows higher and lower energy photons to be processed separately. The glass comprises a front pane with a layer of highly emissive, manganese doped quantum dots deposited onto it, and a second pane of glass comprising a copper-indium-selenide layer.
The front layer absorbs blue and ultraviolet portions of the solar spectrum, leaving the rest to fall on to the CIS layer below.
The use of manganese ions in the front layer is also a key innovation – these quantum dots act as highly emissive impurities, emitting light at wavelengths below the quantum dot absorption.
This re-emitted light is then guided by total internal reflection into solar cells incorporated into the window frame. According to the researchers, this trick allows for almost complete elimination of losses due to self-absorption.
“Because of the strong performance we can achieve with low-cost, solution processable materials, these double pane windows and solar concentrators offer a new way to bring down the cost of solar electricity,” says lead researcher Victor Klimov. “The approach complements exisiting PV technology.”