Polaris solar PV net news: Introduction: the United States national renewable energy laboratory (NationalRenewableEnergyLaboratory,NREL) published by early 2014 all kinds of solar cell conversion efficiency record. Current record for the highest conversion efficiency concentrator type triple junction solar cells is manufactured by sharp created, up to 44.4%. Perovskite-type solar cells to this article in your statistics is 17.9%, but in fact currently perovskite-type solar cell conversion efficiency has been increased to 19.3%.
Just 5 years from 2009 to 2014, perovskite-type solar cell conversion efficiency jumped from 3.8% to 19.3%, improving by a factor of 5 times. Rapid progress the efficiency, cost of cheap, easy, so much so that by the journal Science, named one of the 10 major scientific breakthroughs in 2013.
Perovskite-type batteries in the end is what? Why have such a greater research impact? It really was the dark horse in the solar cell industry right?
1, perovskite-what is it?
(In Russia he discovered calcium Titanium Ore, hidden in the Harvard Museum of natural history Credit:La2O3 (CCBY-SA3.0license))
Perovskite, English name perovskite, is a common metallic crystals of organic compounds, mainly composed of calcium titanate (CaTiO3). 1839 Germany mineral cigar gusitafu·luosi (GustavRose) in Russia on the territory of the Central Ural mountains found a special kind of rock samples and decided to worship the great Geologist in his mind the LevPerovsk obviously this ore.
But then we generally refer to the perovskite cell (full name: methylamine perovskite-type PB-iodide thin-film solar cells) are not made of this ore material, but using similar compounds with perovskite crystal structure.
2, perovskite crystal structure:
(Sketch of perovskite crystal structure)
The structures of perovskite is ABX3 form. Sharing a BX6 in every corner of this structure is octahedral, where b is the metal cation (Sn2+ or Pb2+), x is an anion (Cl-,Br-or I-). Cation in perovskite a material to be used to offset charges reached electrically neutral, it can be a large RADIUS alkali metal ions, or even a molecule.
This particular crystal structure so that it has a lot of unique physical and chemical properties, such as draw optical, electro-catalytic properties, and so on, in the field of chemistry, physics, has a small application. In the perovskite family now includes hundreds of substances, from conductors, semiconductors, insulators, very wide, many of which are synthetic. Solar cells using perovskite (such as CH3NH3PbI3, CH3NH3PbBr3 and CH3NH3PbCl3) belong to the semiconductor, have good light absorption.
3, development of perovskite Jian Cheng: 5 years-from 3.8% to 19.3%
2009 – Gong Banli shadow Yokohama Tong University (TsutomuMiyasaka) by a thin film of perovskite (CH3NH3PbI3 and CH3NH3PbBr3) as a light absorbing layer used in dye-sensitized solar cells, produced the perovskite-type solar cell. Photoelectric conversion rate at that time was 3.8%. Later researchers have improved the battery converted to over 1 time. Conversion efficiency, but also face a fatal problem, that metal halide perovskite easily hydrolyzed liquid electrolyte in the battery led battery low stability, short life.
August 2012 – by gelazier (Gr which tzel) leadership has been achieved by Sungkyunkwan University and Polytechnic of Lausanne laboratory will be a solid hole transport materials (holetransportmaterials,HTM) into solar cells, cell efficiency improving to 10%, also solves the problem of unstable batteries, also easier to package than before.
Henry • Si Naisi 2013 – the University of Oxford (HenrySnaith) battery of TiO2 use in aluminum (Al2O3) in place, not only became the light absorbing layer perovskite also is transfer charge of semiconductor material. Of the perovskite cell conversion efficiency rose to 15%.
August 2014 – UCLA research team led by Chinese scientists like Yang Yang, latest research papers published in the journal Science, said they improved perovskite layers, select the material more suitable for transmission charge for the battery at both ends of the electrodes can collect more, the conversion efficiency of up to 19.3%, became the area’s largest.
4, perovskite battery advantages:
Conversion efficiency and fast-5 years increased from 3.8% to 19.3% in November 2013 and United States scientists have found in the new study, new perovskite (CaTiO3) or solar cell conversion efficiency of up to 50%, twice times the conversion efficiency of solar cells on the market today, this means it has a lot of potential to be dug up;
Often simple fabrication process–a lab using liquid phase deposition, vapor deposition techniques, mixing liquid/vapor deposition processes;
Power generation costs low–and could even be lower than the thermal power.
Building integrated potential-perovskite-type batteries belong to the thin film solar cells, the key is deposited on the glass, you can also control the thickness of each layer and materials to achieve different degrees of transparency, of course, efficiency will be reduced, but this type of application is well worth trying. For example Oxford University laboratory can already make half light (Brown) of the battery. If the integration of lighting and power generation solar cell development goes well, curtain wall decoration, vehicle tinted glass high-rise buildings is expected to become the film and other alternatives.
5, perovskite battery problem:
Toxic-and perovskite materials contain lead, but lead with other types of batteries compared to contain arsenic, gallium, tellurium, cadmium, was only partly right. United States Northwestern University has also developed a Tin instead of lead perovskite-type solar cells, but the cell conversion efficiency are only 6%, now in the early stages of development, and still have space to improve efficiency;
Instability-the lead easily-perovskite oxide evaporation, and when the crystals, water is easy to decompose. If we use the perovskite cell generation, it may seep into the roof or in the soil;
Life is not long-currently, the longest life expectancy of perovskite-type solar cells can be up to 1000 hours, cooperation in research and development by the Huazhong University of science and the Lausanne Federal Polytechnic. While traditional crystalline silicon solar battery life and can be up to 25 years, much longer than the perovskite cell.
Original title: perovskite battery: solar industry stars