Solar energy has become a relatively competitive source of power generation, though an improvement on the existing technology and a further elevation in the conversion efficiency is certainly a good thing. German scientists have recently integrated a nanostructure with a solar cell that is completely different in design to produce a solar cell that may achieve a conversion efficiency of 26%.
Numerous scientists and companies are starting to focus on emerging materials such as perovskite solar cells for the purpose of improving on the conversion efficiency and performance of solar energy, and the relevant development has conformed to the anticipation as the maximum conversion efficiency is now more than 25%, with promising applications expected once challenges, including durability and lifespan, are resolved.
There are also a large group of scientists who are continuing on the R&D of existing silicon solar technology. Modules of a 23% conversion efficiency can already be obtained from the market right now, and another increase in the efficiency would once again lower the cost of solar energy.
The energy losses of solar panels include the non-absorption loss of energy below the silicon energy gap (1.12 eV), thermal loss over the silicon energy gap, as well as compound issues derived from internal defects and contacts. The passivation technology creates a significantly large impact on the increment of conversion efficiency and open circuit voltage for solar energy, while also increases surface energy gap and incident light, or enhances the stability and durability of atomic bonding on the surface. A common technology is PERC.
Now, the Forschungszentrum Jülich (Jülich Research Centre) has introduced a different solar cell structure, which is formed with silicon, silicon dioxide, passivated silicon carbide and conductive silicon carbide, as well as transparent and conductive indium tin oxide from the bottom to the top, and the very top of the cell structure is a fully transparent passivating contact layer.
The Forschungszentrum Jülich first deposited dual layers of pyramid-shaped silicon carbide nanocrystals on the silicon dioxide layer, then produced a transparent indium tin layer through chemical vapor deposition (CVP) and sputter deposition. Malte Köhler, Doctor of IEK-5 and the first author of the thesis, commented that the nanostructure developed by the research team happens to satisfy the passivation technology required by solar cells, and that the ultra-thin transparent TPC layer hardly impacts the incident light, while also capable of high electrical conductivity.
The first cell prototype has exerted an excellent performance at a conversion efficiency of 23.99% (±0.29%), and has been certified by the independent laboratory of the Institute for Solar Energy Research Hamelin (ISFH), where the simulated laboratory also expressed that the TPC technology is able to surpass 26% in conversion efficiency.
Silicon solar cells have been developed sturdily for the past decades, and are now the most matured technology in the solar industry, where a continuous transcendence is required in the future to avoid being replaced by new technology. Kaining Ding, advising professor of the research team, commented that there was never a method in that past that is able to assimilate passivation, transparency, and electrical conduction into one single design, and that the team had also adopted a production method that swiftly integrates with mass production.
(Cover photo source: Forschungszentrum Jülich)