阅读说明：本技术 钛酸钡无机钙钛矿太阳能电池材料 (Barium titanate inorganic perovskite solar cell material ) 是由 张叶 马春兰 陈高远 张加永 葛丽娟 于 2018-05-20 设计创作，主要内容包括：本发明公开一种钛酸钡无机钙钛矿太阳能电池材料,所述太阳能电池材料的化学式为BaTi<Sub>1-<I>x-y</I></Sub>Co<Sub><I>x</I></Sub>Pd<Sub><I>y</I></Sub>O<Sub>3-δ</Sub>,其中,<I>x(The invention discloses a barium titanate inorganic perovskite solar cell material, wherein the chemical formula of the solar cell material is BaTi 1‑ x‑y Co x Pd y O 3‑δ Wherein, in the step (A), x =4.17%， y =4.17%, δ = 4.17%; the solar cell material is based on BaTiO 3 Structural unit constructed as The super cell is of a tetragonal structure, the lattice constant is a = b =11.15 Å, c =11.95 Å, the volume is 1485.90 Å, the super cell contains 24 Ba atoms, 22 Ti atoms, 1 Co atom, 1 Pd atom and 71 oxygen atoms, and the band gap of the solar cell material is 1.4eV ~ 2.0.0 2.0 eV.The efficiency is high.)

1. A barium titanate inorganic perovskite solar cell material is characterized in that: the chemical formula of the solar cell material is BaTi_1-x-y Co _x Pd _y O_3-δWherein, in the step (A),x =4.17%，y=4.17%, δ = 4.17%; the solar cell material is based on BaTiO₃Structural unit constructed asA super-cell having a tetragonal structure with a lattice constant of a = b =11.15 Å, c =11.95 Å, and a volume of 1485.90 Å, the super-cell comprising 24 Ba atoms, 22 Ti atoms, 1 Co atom, 1 Pd atom, and 71 oxygen atoms.

2. The barium titanate inorganic perovskite solar cell material as claimed in claim 1, wherein the band gap of the solar cell material is 1.4eV ~ 2.0.0 eV.

3. The barium titanate inorganic perovskite solar cell material of claim 2, characterized in that: the band gap of the solar cell material is 1.55 eV.

Technical Field

The invention relates to the technical field of solar cell materials, in particular to a barium titanate inorganic perovskite solar cell material.

Background

At present, 80% of world energy sources are from non-renewable fossil energy sources such as coal, petroleum and natural gas, 6% of clean energy sources are from nuclear energy with potential safety hazards, and renewable energy sources (including solar energy) only account for 0.2%. The exhaustion of fossil energy is increasing, people worry about the safety of nuclear energy caused by nuclear power station accidents, and the efficient utilization of solar energy is the best way for solving energy crisis and environmental problems. The solar cell directly converts solar energy into electric energy, which is the most promising renewable energy technology, and how to effectively improve the efficiency of the solar cell is the most important challenge facing the present.

The efficiency of a traditional single junction solar cell is limited by the S-Q efficiency Limit (Shockley-Queisser Limit). Solar cells can be classified into silicon-based solar cells, compound solar cells, and organic-inorganic hybrid perovskite solar cells according to the materials used for the active layer of the single-junction solar cell. The efficiency of the monocrystalline silicon solar cell can reach 25%, but the production cost is higher; the highest conversion efficiency of the polycrystalline silicon solar cell is about 15 percent. The typical representation of a compound solar cell is GaAs with a single junction efficiency of 28.8%. Organic-inorganic hybrid halide perovskite materialsABX ₃ (A=CH₃NH₃, HC(NH₂)₂; B=Pb; X= I, Br, Cl), the energy conversion efficiency reaches 22.7% only in three or four years, and the preparation is easy and the cost is low. However, the general organic-inorganic hybrid halide perovskite solar cell material has two fatal problems: firstly, the organic components in the material cause poor stability, and secondly, the material contains toxic Pb. One fundamental solution to the stability problem is the development of inorganic perovskite solar cells. The professor warrior professor in river-south university successfully prepares a product based on FTO/NiO_x/CsPbI₂Br/[email protected]₆₀the organic component is not necessary for the high-efficiency perovskite solar cell material. Riming Nie et al successfully prepared a lead-free high-efficiency perovskite solar cell material, namely, ammonium methyl antimony sulfide diiodide (MASbSI)₂) It can be seen that Pb is also not required for high efficiency perovskite solar cell materials. L, Debbichi et al discovered an inorganic non-lead mixed-valence perovskite Cs₂Au₂I₆With a band gap value of 1.31eV, close to the ideal band gap value for the photovoltaic material, indicating that neither organic components nor lead are necessary for a high efficiency perovskite photovoltaic material. Ming-Gang Ju et al found halogen-free SrSnSe₃And SrSnS₃Are very good photovoltaic materials, indicating that halogens are not necessary for efficient perovskite solar cell materials either. Haimin Li et al found PbTiO based₃The doped perovskite oxide has very good photovoltaic properties, indicating that perovskite oxides may also have very good photovoltaic properties.

Combining the above results, organic Component (CH)₃NH₃；HC(NH₂)₂) Pb, and halogen elements (I, Br, Cl) are not essential factors for the material to have high photoelectric conversion efficiency. The invention aims to design an inorganic nontoxic perovskite solar cell material which does not contain organic components and Pb.

The key factors influencing the photoelectric conversion efficiency of the solar cell material comprise the absorption capacity of the material on solar energy (related to the material band gap), the storage capacity on photo-generated charges (related to the material polarization characteristic) and the carrier mobility (related to the electron-hole effective mass). the material with the band gap of 1.4eV ~ 2.0.0 eV has high solar energy absorption efficiency and can generate more photo-generated carriers, the material with good polarization characteristic can effectively separate the photo-generated carriers, and the high carrier mobility means that the photo-generated carriers can be efficiently guided out.

Originally, photovoltaic materials with high photoelectric conversion efficiency were developed and often contained lead. Lead-free ferroelectric perovskite photovoltaic materials are being developed for environmental reasons. At present, most inorganic solid oxide ferroelectrics have band gaps larger than 3 eV, mainly absorb the solar spectrum of an ultraviolet region, and because the ultraviolet light only contains 8 percent of the solar spectrum,And thus the solar energy conversion efficiency is too low. In order to improve the conversion efficiency, the band gap of these ferroelectric perovskite materials must be reduced. Barium titanate, a typical perovskite material, has good polarization characteristics, but the band gap is too large (3.25 eV) to absorb solar energy well. Research shows that doping can change lead-free BaTiO₃Band gap of (b): sr is used to replace Ba (doping concentration is 0.1-0.5), and BaTiO₃The band gap of (a) increases with increasing doping concentration; zn is used for replacing Ti (doping concentration is 0.01-0.05), BaTiO₃The band gap of (a) also increases with increasing doping concentration; experiments of Y.W. Li and the like find that Co is used for replacing Ti (the doping concentration is 0.01-0.1), the band gap of the film is reduced along with the increase of the doping concentration, but the band gap of the compound in the doping concentration range studied by the Co and Li is still larger than 3.0 eV, and solar energy cannot be efficiently absorbed. Therefore, how to research a barium titanate inorganic perovskite solar cell material which is stable and nontoxic, has good photoelectric conversion efficiency and is an effort for technicians in the field.

Disclosure of Invention

The invention aims to provide a barium titanate inorganic perovskite solar cell material which is inorganic, stable and nontoxic, has good polarization characteristic and high carrier mobility, and is high in photoelectric conversion efficiency.

in order to achieve the purpose, the invention adopts the technical scheme that: a barium titanate inorganic perovskite solar cell material having the chemical formula BaTi1-x-yCoxPdyO3- δ, wherein x =4.17%, y =4.17%, δ = 4.17%; the solar cell material is based on a BaTiO3 structural unit and is constructed byA super-cell having a tetragonal structure with a lattice constant of a = b =11.15 Å, c =11.95 Å, and a volume of 1485.90 Å, the super-cell comprising 24 Ba atoms, 22 Ti atoms, 1 Co atom, 1 Pd atom, and 71 oxygen atoms.

the further improved scheme in the technical scheme is as follows:

1. In the scheme, the band gap of the solar cell material is 1.4eV ~ 2.0.0 eV.

2. In the scheme, the band gap of the solar cell material is 1.55 eV.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

According to the barium titanate inorganic perovskite solar cell material, as the Co element is doped in barium titanate, a Co _3d energy band slightly crosses over a Fermi surface to generate partial holes, and when oxygen vacancies exist, electrons provided by the oxygen vacancies fill the holes to generate a new valence band top with a higher energy level, so that the band gap is reduced; because the Co element is doped and the Pd element is simultaneously doped, the Pd-4 d state introduced by the Pd doping provides a new conduction band bottom which is closer to a Fermi surface than the original Ti-3 d conduction band bottom, thereby reducing the band gap. For the (Co, Pd) Co-doping situation, the valence band is lifted up, and the conduction band bottom is lowered, so that the band gap is reduced, the (Co, Pd) Co-doping situation is stable and non-toxic, and the (Co, Pd) Co-doping situation has the advantages of good polarization characteristic, high carrier mobility and high photoelectric conversion efficiency.

Drawings

FIG. 1 is a first crystal structure diagram of a barium titanate inorganic perovskite solar cell material of the present invention;

FIG. 2 is a crystal structure diagram II of the barium titanate inorganic perovskite solar cell material of the invention;

FIG. 3 is a state density diagram of the barium titanate inorganic perovskite solar cell material of the invention.

Detailed Description