A strategy to improve the efficiency and also long-term stability of perovskite solar cells

• Over the past couple of years, scientists have actually been attempting to develop brand-new layouts for perovskite solar cells that could boost their performance, effectiveness and stability over time. One feasible means of accomplishing this is to integrate 2-D as well as 3-D halide perovskites in order to leverage the beneficial properties of these 2 different sorts of perovskites.

The two-dimensional crystal framework of 2-D halide perovskites is highly resistant to moisture; therefore, it might assist to increase the performance and sturdiness of solar cells with a light-absorbing 3-D halide perovskite layer. Nonetheless, a lot of the techniques for combining 2-D as well as 3-D halide perovskites suggested up until now simply require blending these two products with each other (e.g., mixing 2-D forerunners with a solution-based 3-D perovskite or responding 2-D forerunner solutions on top of a 3-D perovskite layer).

Scientists at Seoul National University and also Korea University have recently devised a different technique for developing solar cells that integrate 2-D as well as 3-D halide perovskites. This technique, laid out in a paper published in Nature Power, could aid to all at once boost both the effectiveness and also long-term stability of these cells.

" Although the mixing of different perovskite films has some favorable result on effectiveness and moisture security, the 2-D formation via the service procedure with the chain reaction of the 2-D forerunner with 3-D halide has restrictions, such as vulnerability to warm and problem in applying junctions for internal electric field layout in the gadget as a result of an unintended quasi-2-D stage formation," Prof. Jun Hong Noh, one of the researchers that executed the study, told TechXplore. "We have actually tried to solve this trouble."

To get rid of the restrictions of previously recommended methods for creating 2-D/3-D halide perovskite-based solar cells, Prof. Noh and also his coworkers attempted to produce an ideal junction between a solar cell's light-absorbing layer (with a slim bandgap) and also the useful 2-D layer (with a vast bandgap). This functional layer is discovered in lots of existing high-efficiency solar cell frameworks, consisting of gallium arsenide (GaAs) and heterojunction with intrinsic thin layer (HIT) silicon solar cells.

GaAs as well as HIT solar cells use a III-V semiconductor (AlGaAs) and amorphous silicon (a-Si), specifically, as a functional layer with a large bandgap, in order to form a correct internal electrical field. In these solar cells, the functional layer and the light-absorbing layer are usually identical. To develop their solar cells, Prof. Noh as well as his coworkers thus ensured that they made use of a 2-D halide perovskite with a large bandgap that was identical with the 3-D halide perovskite they chose.

" In order to form an undamaged 2-D/3-D junction, we pertained to the conclusion that the option process should be omitted when developing the junction," Prof. Noh stated. "That is exactly how the solid-phase in-plane development (SIG) process was birthed. In the SIG procedure, a 3-D film and also a 2-D film are independently prepared, the 2-D film is stacked on top of the 3-D film to ensure that they encounter each other, and afterwards warm and also stress are put on generate the 2-D film to expand on the 3-D layer."

Using this unique style method, the scientists had the ability to expand a very crystalline 2-D film on top of the 3-D halide perovskite film without harming it and also without utilizing solvents. This resulted in the development of an undamaged 2-D/3-D junction.

Prof. Noh and also his colleagues found that their approach does not result in the unplanned development of a quasi-2-D film, which can sometimes occur when 2-D and 3-D halide perovskite films are blended together. The resulting structure is thermally steady, while likewise allowing the scientists to quickly manage the density of the 2-D film and also control the 2-D/3-D junction's inner electric field.

" Our method can all at once boost performance as well as long-term security of perovskite solar cells," Prof. Noh claimed. "On top of that, we offered a method to make the undamaged junction (halide/halide) in between homogeneous halides, as opposed to the junction in between heterogeneous materials (i.e., halide/oxides or halide/organics), which is the conventional tool structure up until now in perovskite solar cells."

The layout strategy introduced by Prof. Noh as well as his associates might soon be made use of to produce 2-D/3-D halide junction perovskite solar cells that have both a high effectiveness and also a high thermal security. In the future, their job can additionally influence other research study teams to employ the very same technique or develop comparable strategies to enhance the efficiency of perovskite-based solar cells.

" In this recent study, we made use of butylammonium lead iodide (BA2PbI4), the easiest framework among 2-D halide perovskites," Prof. Noh said. "Nonetheless, research exploring the application of brand-new 2-D perovskites is underway for a better 2-D/3-D junction style. Via this, we wish that we will certainly have the ability to carry out a high-efficiency perovskite solar cell, such as GaAs."