Solar energy is a very important part of modern alternative power engineering. New battery types tend to appear regularly and quickly become popular. Researchers work on making solar batteries more efficient – making their efficiency coefficient increase from existing 20 per cent up to 30 per cent. Russian scientists used a different approach – their batteries, made of multicrystalline silicon, have common efficiency coefficient, but they are much more cheap than analogues.

BMost solar batteries in the world are currently made of silicon. Highest efficiency is achieved, when pure monocrystalline silicon is used for this purpose. However, monocrystalline silicon has an extremely effort-consuming production process, because it requires close attention on adherence to crystal growing specifications. Multicrystalline silicon, which is an accidental combination of various monocrystalline lattices of silicon, is much easier in production. Experimental batteries have efficiency coefficient of about 15 per cent, which is quite good, moreover, production process of such batteries is much easier, and that is why their price is reasonable.

 

 

Russian physicists and engineers have united their efforts in order to build solar cells from multicrystalline unstructured silicone with efficiency coefficient of 15.9 per cent. All photoelectric cells are based on a well known physical phenomenon – photoelectric effect, which is emission of electron by matter after being exposed to sunlight. Photoelectric cells usually consist of two components: a semiconducting part, which emits electrons, and an electric current collector. Layers of multicrystalline silicon are additionally doped with atoms of phosphorus and boron for creating zones of different conductivity in a semiconducting area. One of these zones makes electricity with the help of electrons, and another – by electron vacancies, so-called electron holes. The interface between these two conductivity zones is where highly efficient photoelectric effect is observed. Surface of the semiconducting area is covered with a special conducting oxide, on which surface a copper grid for electric current collection – this is why new technology is different from already existing ones.

Russian researchers have made experimental photoelectric LGCell (this is the name of the technology) elements of and performed expensive studies of their behavior when exposed to atomic hydrogen. The results fully agreed with what had been predicted for that cell – doping with phosphorus and boron, as well as adding copper grid, provided relative structure ordering of multicrystalline silicon, thus improving efficiency of these batteries.

New semiconducting plates were later used for building experimental samples of photoelectric elements. First tests revealed that battery efficiency had dropped, when exposed to light with short wavelength (less than 300 nanometers). The explanation was peculiar structure of battery’s surface layer, and the solution was following – chemical etching was demonstrated to significantly improve efficiency of a photoelectric cell.

Photoelectric efficiency of a Russian innovation appears to be 15.9%, which is quite close to existing standard of 16.1% for such kind of batteries.