Solar energy is one of the cleanest and abundant form of free energy sources available. Already, the contribution of solar energy have a significant impact on human needs, solar technology is a growing, multibillion-dollar industry. But today’s commercial solar cells, most often made from silicon, typically convert sunlight into electricity with an efficiency of only 10 percent to 20 percent, although some test cells do a little better. This efficiency factor is the main concern for the scientists to deal with. Theoretically maximum efficiency of a solar cell can reach only up to 31 percent due to the electronic properties of the silicon material.
Researchers from Valencia have proposed a promising way to improve solar efficiency. They have successfully coupled two different components halide perovskites and colloidal quantum dots (QDs) and have come to a conclusion that the interaction between these two materials could improve LED and solar technologies. Both halide perovskites and colloidal quantum dots are separately known for their optoelectronic properties when interacted together these materials produce much longer wavelengths than can be achieved by either material alone.
Perovskite materials are the fastest advance solar technology in the photo-voltaic industry to date, plus they are cheap to produce, simple to manufacture and extremely efficient. The perovskite materials have a lot of potential to improve the efficiency further and are still very much in the research area. They are also used in LED technology.
Quantum dots (QDs), on the other hand, are semiconductor devices that tightly restrain electrons or holes in all three spatial dimensions. They can be made via several possible routes including colloidal synthesis, plasma synthesis, or mechanical fabrication. Quantum Dots has the ability to tune whatever wavelengths light is been emitted at it. They are also very useful in both LEDs and solar cells.
The two materials were coupled together in a lab research experiment and the results showed a new “exciplex” state where light can be emitted at much longer wavelengths, reaching well into the infrared spectrum. It also allowed controlling over the emission color by varying the applied voltage. Both the material (perovskite and the QDs) emitted light at a different color, each of which can be weighted within the overall light emission to pick out the desired color.
The success of this experiments has paved a new way in LED designing where it can now emit light over both the visible and infrared spectrum at the same time, which have both theoretical and practical aspects in the field of telecommunications.
Presently solar cells can only transform light emitted over a relatively
narrow band of wavelengths. But if it is possible to produce light at longer wavelengths via an electrical input, then the theoretical procedure of obtaining electrical energy by absorbing light of longer wavelengths will also be made possible, thereby helping in increasing the efficiency of solar cells.
The result of these two materials will have a greater impact on improving solar technology and will help solar power to affirm its superiority to fossil fuels as a sustainable motive force for civilization’s continued prosperity.