According to foreign media New Atlas, silicon has always been the preferred material for solar cell technology because of its low cost, stability, and high efficiency. Unfortunately, the conversion efficiency of silicon solar cells is rapidly approaching its theoretical limit, but with Other material pairings may help break the ceiling. Now, researchers at the Swiss Federal Institute of Technology in Lausanne (EPFL) and the Swiss Center for Electronics and Microtechnologies (CSEM) have developed a new combination of silicon and perovskite solar cell technology. , and reported an efficiency record of 25.2% - this is an entirely new record for this solar cell combination technology.
At present, the efficiency of silicon solar cells on the market can reach as high as 20% to 22%, which is not bad, but it can not make the technology have more room for development. In recent years, perovskite as an ideal alternative, Its efficiency increased from 3.8% in 2009 to more than 20% in 2016. Nevertheless, its price is more expensive than ordinary silicon solar cells, and has its own upper limit of efficiency.
The use of perovskite and silicon in a solar cell may help to take advantage of these two materials. Perovskite is better at converting green and blue light into electricity, while silicon is dedicated to red and infrared light. So they can capture a wider spectral range.
'By combining these two materials, we can make maximum use of the solar spectrum and increase the amount of power generated,' said research authors Florent Sahli and Jérémie Werner. 'The calculations and work done by us show that 30% efficiency should be fast Can be achieved. '
The team’s new silicon-perovskite solar cell has achieved a 25.2% efficiency. This exceeds the tandem-structured solar cell that was developed in 2015 by stacking a monocrystalline silicon solar cell and a perovskite solar cell. The efficiency is only 13.7%. The main hurdle of these tandem cells is during the manufacturing process. Usually, perovskites will deposit as liquid on the surface, but the texture of silicon makes it difficult. It consists of a large number of pyramids about five microns high. ' Structure composition, can better capture and absorb light.
Sahli said: 'So far, the standard method for manufacturing perovskite/silicon tandem cells is to flatten the 'pyramid' of silicon cells, but this will degrade their optical performance and therefore reduce their performance, and then deposit perovskite cells. At its top. It also adds steps to the manufacturing process.
In this study, scientists first used evaporation to create an inorganic base covering the 'pyramid'. Then, the liquid organic solution was added by spin coating and it penetrated into the pores of the base layer. Finally, the team heated the substrate to 150°C ( 302°F), so that the perovskite crystallizes on top and forms a thin film covering the entire surface of the silicon. The researchers stated that this process is relatively simple and can be incorporated into an existing production line in a few extra steps. Will help new tandem battery production without over-costing.
The study was published in the journal Nature-Materials.
