There is no denying that solar cells are slowly gaining traction, however, most solar cells are still slow in converting sunlight into electricity since they don’t harvest the entire spectrum of light. This is the reason research groups are looking for ways to improve the efficiency of solar cells while reducing their cost.
Working on the same lines a research team at the University of Notre Dame is trying to build affordable solar cells by replacing silicon, the main ingredient in a solar cell, with quantum dots – nanometer-sized crystals that glow when stimulated by an external source such as ultraviolet light. Quantum dots are cheaper to turn into solar cells as they don’t rely on expensive chip manufacturing techniques.
Moreover, the quantum dots can be tuned to generate electricity from a specific wavelength of light, allowing them to convert electricity from a much broader spectrum. The team here layered three types of quantum dots made from a mix of cadmium, sulfur and selenium that are tuned to respond to green, orange and red light. After fabricating the solar cell with quantum dots, the team realized that the solar cells performed better than their expectations and had an efficiency more than what they had actually calculated.
While the researchers aren’t exactly sure about what causes the boost in efficiency, but the reason might be the transfer of light energy rather than electrons across dots. Apart from its use in affordable solar cells, Discovery News notes that quantum dots can also be made into different shapes and can be spread on surfaces like a paint, adding to their possible application areas.