A method to support 3D/2D perovskite heterostructures for solar cells
- Hybrid perovskite solar cells (PSCs) constructed from organic and also inorganic products are highly promising energy services that can help to decrease carbon emissions worldwide. In the last few years, these cells' power-conversion efficiencies (PCEs) have actually improved substantially, ultimately surpassing 25%.
A vital turning point in the construction of efficient PSCs was making use of 2D and also quasi-2D changed 3D perovskite heterostructures (i.e., structures consisted of 3D and also 2D perovskite materials). These structures have a number of beneficial qualities, for instance they enable the passivation of defects as well as a positive band alignment, which in turn improves the cells' open-change voltage and fill variable.
3D/2D heterostructures are typically produced by spin finishing an organic cation salt service in addition to a 3D perovskite material and creating a slim 2D perovskite layer on its surface area. This procedure, nonetheless, can facilitate the subsequent destruction of the heterostructures in some conditions, as a result of the diffusion of ions between the 2D perovskite surface area and underlying bulk 3D perovskite.
Scientists at Huazhong University of Science and also Technology, Wuhan University of Technology and University of Toronto lately presented a new approach for fabricating much more steady 3D/2D heterostructures, avoiding their deterioration. Their approach, presented in a paper released in Nature Energy, involves the intro of an additional layer in between the frameworks; 3D and also 2D perovskite layers.
" The ionic diffusion between the surface area 2D and mass 3D perovskites causes the degradation of the 3D/2D perovskite heterostructures and also restricts the lasting stability of PSCs," Long Luo, Haipeng Zeng and also their associates wrote in their paper. "We incorporate a cross-linked polymer (CLP) on the top of a 3D perovskite layer and afterwards deposit a 2D perovskite layer via a vapor-assisted two-step process to form a 3D/CLP/2D perovskite heterostructure."
Basically, Luo, Zeng and also their coworkers recommended presenting an interlayer in between 3D bulk perovskites and also 2D surface perovskites in 3D/2D heterostructures. This interlayer is constructed from a cross-linked polymer (CLP) that can inhibit ion diffusion without affecting the charge transportation between the 3D and also 2D perovskite layers.
" Photoluminescence ranges and also thickness-profiled elemental evaluation show that the CLP supports the heterostructure by inhibiting the diffusion of cations (formamidinium, FA+ and 4-fluorophenylethylammonium, 4F-PEA+) between the 2D and also 3D perovskites," Luo as well as his coworkers described in their paper.
To evaluate the performance of their upgraded 3D/2D heterostructure layout, the researchers utilized it to produce a series of small-area solar cells, in addition to mini solar modules. These cells and modules obtained impressive results, as they showed up dramatically much more secure than perovskite-based cells and modules with standard 3D/2D heterostructure styles.
" For devices based upon carbon electrodes, we report small-area tools with an effectiveness of 21.2% as well as mini-modules with an effectiveness of 19.6%," Luo and his coworkers wrote in their paper. "Gadget keep 90% of first performance after 4,390 hours procedure under optimal power point monitoring as well as one-sun illumination at raised temperature levels."
In the future, the new layout presented by Luo as well as his associates can help to maintain solar cells based upon 3D/2D perovskite heterostructures, without affecting their effectiveness. Furthermore, their research might inspire other teams to devise similar techniques that introduce an interlayer in between 3D and 2D perovskite layers to stop deterioration caused by ionic diffusion.