CN108493344A - Shell-and-core structure perovskite nano-wire array solar cell - Google Patents

Abstract

The invention discloses a shell-core structure perovskite nanowire array solar cell, which comprises an upper electrode and a lower electrode arranged oppositely, and a core layer is arranged on the upper part of the lower electrode, and the core layer includes a layered base and an array The columnar part distributed on the upper surface of the base, a shell layer made of perovskite is arranged between the core layer and the upper electrode, and the shell layer is covered and attached to the core layer, and the lower electrode of the upper electrode The surface is attached to the upper end surface of the shell. The core-shell structure perovskite nanowire array solar cell provided by the present invention has a novel structure, is easy to implement, reduces the carrier recombination rate, increases the effective carrier concentration, and shortens the carrier transport path, thereby greatly improving photoelectric conversion. efficiency.

Description

Shell-core structure perovskite nanowire array solar cells

technical field

The invention belongs to the technical field of solar power generation, and in particular relates to a shell-core structure perovskite nanowire array solar cell.

Background technique

Energy is the material basis for the survival and development of human society. The development and utilization of renewable energy is an important way to solve energy problems, and solar energy is a widely distributed, inexhaustible, clean and pollution-free renewable energy.

At present, the most widely used form of solar cells is thin-film solar cells, and the most widely studied light-absorbing material is silicon-based materials. However, the photoelectric conversion efficiency of silicon-based solar cells is close to the theoretical limit, and there are disadvantages such as high price, large energy consumption, and heavy pollution. . Therefore, researchers are thinking about replacing them with other materials. In the past ten years, based on silicon solar cells, new photovoltaic materials such as multi-element compounds, organic compounds, and organic-inorganic hybrid perovskites have emerged. Multi-component compound thin-film solar cells (cadmium telluride (CdTe), copper indium gallium selenide (CIGS), copper zinc tin sulfur (CZTS), etc.) contain rare elements, so the cost is high, and its composition is not easy to control, which is not conducive to its Large-scale commercial applications; organic compound solar cells are simple to prepare, low in cost, light in weight and can be made into flexible devices, but their poor stability and short life are also not conducive to large-scale applications; organic-inorganic hybrid perovskite solar cells Combining the advantages of inorganic solar cell materials and organic solar cell materials, it has the characteristics of strong light harvesting ability, excellent charge transport ability and high defect tolerance, but its stability and life are still not ideal, and it is far from commercial application. There is still a long way to go.

Contents of the invention

In order to solve the above technical problems, the present invention provides a perovskite nanowire array solar cell with a core-shell structure, which has higher photoelectric conversion efficiency.

To achieve the above object, the technical scheme of the present invention is as follows:

A perovskite nanowire array solar cell with a shell-core structure, comprising an upper electrode and a lower electrode arranged oppositely, the main point of which is that a core layer is arranged on the upper part of the lower electrode, and the core layer includes a layered base and an array The columnar part distributed on the upper surface of the base, a shell layer made of perovskite is arranged between the core layer and the upper electrode, and the shell layer is covered and attached to the core layer, and the lower electrode of the upper electrode The surface is attached to the upper end surface of the shell.

With the above structure, the shell layer is made of perovskite material, and the core layer is an electron/hole transport layer. This special shell core layer forms a special one-dimensional structure of a shell-core structure nanowire array, which has many Advantages: easy single crystallization, which can reduce the hole-electron recombination rate; provide direct transport channels for carriers, increase the diffusion length and life of carriers; easily cause resonance of light intensity to produce light concentration, which can break The Shockley-Queisser efficiency limit exists in the photoelectric conversion efficiency of the solar cell, so it has a higher photoelectric conversion efficiency; the nanowire array has the function of anti-reflection, so that it can absorb more incident light, so that it can provide more many photogenerated electron-hole pairs. Under the illumination, the light incident from the upper electrode is fully absorbed by the shell layer to generate electron-hole pairs, and then electrons and holes are separated inside the shell layer, and the separated electrons (holes) migrate to the lower electrode through the core layer, corresponding The holes (electrons) are transported along the shell layer to the upper electrode, thus, the electrons and holes are transported in the shell layer and the core layer respectively, thereby reducing the carrier recombination rate and increasing the effective carrier concentration. The carrier transport path is shortened, so higher photoelectric conversion efficiency is realized.

Preferably, the shell layer includes a layered part and a cylindrical part arranged in an array on the upper part of the layered part, the lower surface of the layered part is bonded to the upper surface of the base, and each of the cylindrical parts is sleeved on the corresponding on the columnar part, and the inner surface is attached to the outer surface of the corresponding columnar part, and the upper end surface is attached to the lower surface of the upper electrode. Adopting the above structure has a larger surface area and effectively improves the absorption efficiency of photons.

As a preference: the cylindrical parts are all cylindrical. Adopting the above structure, it is stable, reliable and easy to manufacture.

As a preference: among the upper electrode and the lower electrode, at least the upper electrode is a flexible electrode. With the above structure, there may be manufacturing errors in the height of the upper end surface of each cylindrical portion of the shell layer, but using a flexible electrode for the upper electrode can effectively overcome this problem and reduce the difficulty of manufacturing the solar cell.

As a preference: the lower electrode is conductive glass, which has better supporting strength and is beneficial to the manufacture of solar cells.

As a preference: the perovskite is a low-dimensional perovskite, which can generate stable excitons, has good stability, and improves the photoelectric conversion efficiency of the solar cell.

Compared with prior art, the beneficial effect of the present invention is:

The core-shell structure perovskite nanowire array solar cell provided by the present invention has a novel structure, is easy to implement, reduces the carrier recombination rate, increases the effective carrier concentration, and shortens the carrier transport path, thereby greatly improving photoelectric conversion. efficiency.

Description of drawings

Fig. 1 is a schematic diagram of the internal structure of the present invention;

Fig. 2 is a structural schematic diagram of the present invention.

Detailed ways

The present invention will be further described below in conjunction with embodiment and accompanying drawing.

As shown in Figure 1 and Figure 2, a perovskite nanowire array solar cell with a shell-core structure comprises an upper electrode 1 and a lower electrode 2 arranged oppositely, a core layer 3 is arranged on the top of the lower electrode 2, and A shell layer 4 made of low-dimensional perovskite is arranged between the core layer 3 and the upper electrode 1, and the shell layer 4 is covered and attached to the core layer 3. The lower surface of the upper electrode 1 is in contact with the The upper end surface of the shell layer 4 is bonded.

Under the light, the incident light is incident from the upper electrode 1 and is fully absorbed by the shell layer 4 to generate electron-hole pairs, and then the electron-hole pairs are separated from the electrons and holes inside the shell layer 4, and the separated electrons pass through the core layer 3 After reaching the lower electrode 2, the holes are transported along the shell layer 4 to the upper electrode 1; or the separated holes pass through the core layer 3 to the lower electrode 2, and the electrons are transported along the shell layer 4 to the upper electrode 1.

The core layer 3 includes a layered base 31 and an array of columnar portions 32 distributed on the upper surface of the base 31, wherein the lower surface of the base 31 is bonded to the upper surface of the lower electrode 2, and the columnar portions 32 are all large and small. same cylindrical shape. The shell layer 4 includes a layered portion 41 and an array of cylindrical portions 42 distributed on the top of the layered portion 41. The lower surface of the layered portion 41 is attached to the upper surface of the base portion 31. Each of the cylindrical portions 42 Covered on the corresponding columnar portion 32 , and the inner surface is attached to the outer surface of the corresponding columnar portion 32 , and the upper end surface is attached to the lower surface of the upper electrode 1 .

Since the height of the upper end surface of each cylindrical portion 42 of the shell 4 may have tolerances, the use of a flexible electrode for the upper electrode 1 can effectively overcome this problem and reduce the difficulty of manufacturing the solar cell. At the same time, in order to further reduce the manufacturing difficulty of the solar cell, the lower electrode 2 is made of conductive glass to have higher supporting strength.

Finally, it should be noted that the above description is only a preferred embodiment of the present invention, and those of ordinary skill in the art can make a variety of similar implementations under the inspiration of the present invention without violating the purpose and claims of the present invention. It means that such transformations all fall within the protection scope of the present invention.

Claims (6)

1. A core-shell structure perovskite nanowire array solar cell, comprising an upper electrode (1) and a lower electrode (2) arranged oppositely, characterized in that: a core layer is arranged on the top of the lower electrode (2) (3), the core layer (3) includes a layered base (31) and a columnar portion (32) arrayed on the upper surface of the base (31), between the core layer (3) and the upper electrode (1) A shell layer (4) made of perovskite is arranged between, and the shell layer (4) is covered and bonded on the core layer (3), and the lower surface of the upper electrode (1) and the shell layer (4) ) on the upper end surface fit. 2. The core-shell structure perovskite nanowire array solar cell according to claim 1, characterized in that: the shell (4) includes a layered part (41) and the array is distributed on the upper part of the layered part (41) The cylindrical part (42), the lower surface of the layered part (41) is attached to the upper surface of the base part (31), and each of the cylindrical parts (42) is sleeved on the corresponding columnar part (32), And the inner surface is attached to the outer surface of the corresponding columnar part (32), and the upper end surface is attached to the lower surface of the upper electrode (1). 3. The shell-core structure perovskite nanowire array solar cell according to claim 1, characterized in that: the cylindrical parts (42) are all cylindrical. 4. The core-shell structure perovskite nanowire array solar cell according to claim 1, characterized in that: among the upper electrode (1) and the lower electrode (2), at least the upper electrode (1) is a flexible electrode. 5. The core-shell structure perovskite nanowire array solar cell according to claim 4, characterized in that: the lower electrode (2) is conductive glass. 6 . The core-shell structure perovskite nanowire array solar cell according to claim 1 , wherein the perovskite is a low-dimensional perovskite.