Perovskite solar cells recycle light in order to increase efficiency within the power-producing structures. Using hybrid lead-halide perovskites, researchers believe they may be able to pave the way to a new generation of solar cells which reuse photons of light.
Hybrid lead-halide perovskites are inexpensive and simple to manufacture. Solar cells based on this group of materials are already nearly as efficient as their silicon counterparts. Researchers say that the findings could lead to higher gains in solar cell efficiency.
"It's a massive demonstration of the quality of this material and opens the door to maximizing the efficiency of solar cells. The fabrication methods that would be required to exploit this phenomenon are not complicated, and that should boost the efficiency of this technology significantly beyond what we have been able to achieve until now," said Felix Deschler of Cavendish Laboratory.
Photon recycling is accomplished through a relatively simple process. Light falls on the cell, producing electricity. When electrical charges recombine, the energy is re-released in the form of additional photons, which can then strike other molecules in the matrix. This ability to reabsorb photons is unique to perovskite cell, as far as researchers know today.
Experimental solar cells manufactured from silicon may achieve energies up to 44 percent. However, commercial units are typically mired at about half the rate of power conversion. Researchers are looking to greatly increase the efficiency of these systems, in order to lower costs of energy production. Collectors using high-gain cells may bring electricity to developing nations, where conventional generators are uneconomical.
The first generation of solar cells was developed in 1875 by William Grylls Adams and his student, Richard Day. Back then, the pair of researchers discovered selenium produced electricity when exposed to light. Although this first solar cell was highly inefficient, this discovery was the first proof that electricity could be produced artificially without the use of moving parts. The first silicon solar cells were developed in 1953.
Photon recycling may be applied not just to solar cells, but also in light-emitting diodes (LED's), taking advantage of the unique qualities of perovskite materials.
Development of hybrid lead-halide perovskite solar cells and discovery of their ability to recycle photons was published in the journal Science.