Silicon solar cell efficiency is expected to rise to 35%, by changing the passivation layer material

In fact from a global perspective, pv industry is a leading global policy market. Germany, the United States and Japan and other developed countries also need policy subsidies and government planning. From this perspective, the industry has not fully into a state of the market law of development, industrial structure is not stable.

the researchers designed a new type of silicon solar cell, by changing the passivation layer material limit, enhance the efficiency of the silicon battery energy conversion can be from the current 29% to about 35%.

at the Massachusetts institute of technology has a communique said the new battery by school personnel and institutions such as the United States at Princeton university, peer design, use & other; Singlet exciton fission & throughout; Principle, strengthen the use of high-energy photon energy.

in solar cells, molecules to release electrons, photons materials generate an electric current. Usually a photon can inspire an electron, the remainder of the high-energy photons will be in the form of heat energy is lost.

after it has been found that in four benzene and some organic materials, such as a molecular absorption after a high-energy photons, energy can be transferred to another molecule, eventually produce two electrons, this phenomenon is called & other; Singlet exciton fission & throughout; 。 In theory, on the silicon covering a layer of tetracene, can use a high-energy photons get two electrons, but how to make & other; Singlet exciton fission & throughout; The two electron transfer to the silicon material is a key problem.

in order to ensure that the battery efficiency and durability, silicon material must have a surface passivation layer. And four electronic must through the passivation layer is formed in benzene, to get to silicon. Relative to the electron transfer ability, the passivation layer is too thick.

the new scheme is the key to using hafnium oxide of nitrogen was carried out on the silicon passivation and the passivation layer thickness is only 0. 8 nanometers ( A nanometer is equal to the billionths of a metre) , can allow more electrons through. Studies have shown that tetracene each absorbs a photon, with an average of 1. Three electrons can be through the nitrogen oxide hafnium passivation layer, transferred to silicon material.

the relevant papers have been published in the British journal nature. Researchers say new battery efficiency far from theoretical limits, still need to improve, but effective test proves that the key step. The proposal did not into the design of the complex, and it may make a battery overall thinner.