In a world first, an international research team based in Melbourne, Australia, has developed a way to boost the output of the next generation of solar cells by creating a more efficient dye that makes dye-sensitive solar cells (DSSC) perform better than previous versions.

Scientists at Monash have collaborated with colleagues from the universities of Wollongong (Australia) and Ulm (Germany) to produce tandem dye-sensitized solar cells with a three-fold increase in energy conversion efficiency compared with previously reported tandem dye-sensitized solar cells.

Lead researcher Dr Udo Bach, from Monash, was hopeful the breakthrough would increase the energy generation performance of the cells and make them a viable and competitive alternative to traditional silicon solar cells.

The more efficient type of dye the scientists have created makes the operation of inverse dye-sensitized solar cells much more efficient.

The researchers say that when they combined two types of dye-sensitized solar cell - one inverse and the other classic - into a simple stack, it was the first time they were able to produce a tandem solar cell that exceeded the efficiency of its individual components.

"The tandem approach - stacking many solar cells together - has been successfully used in conventional photovoltaic devices to maximize energy generation, but there have been obstacles in doing this with dye-sensitized cells because there has not been a method for creating an inverse system that would allow dye molecules to efficiently pass on positive charges to a semiconductor when illuminated with light," Dr Bach said.

"Inverse dye-sensitized solar cells are the key to producing dye-sensitized tandem solar cells, but the challenge has been to find a way to make them perform more effectively. By creating a way of making inverse dye-sensitized solar cells operate very efficiently we have opened the way for dye-sensitized tandem solar cells to become a commercial reality."

Disappointingly, in the past DSSC have performed below that of silicon solar cells even after many years of research. DSSC have great potential because of their relative inexpensive and easy methods of fabrication.

Dr Bach’s findings, detailed in a paper published in Nature Materials, are said to be an important milestone in the ongoing development of viable and efficient solar cell technology.

"While this new tandem technology is still in its early infancy, it represents an important first step towards the development of the next generation of solar cells that can be produced at low cost and with energy efficient production methods," he said.

"With this innovation we are one step closer to the creation of a cost-efficient and carbon-neutral energy source."