Inkjet Printing of Quasi‐2D Perovskite Layers with Optimized Drying Protocol for Efficient Solar Cells

Abstract

perovskites remains one of the main challenges, adding risk to the long-term reliability of these devices. [3] Recently, perovskite compositions, which induce structures of reduced dimensionality, were reported as an interesting family of compounds, exhibiting promising environmental stability and effective photovoltaic performance parameters. [4,5] Within that category, Ruddlesden-Popper perovskite types were most often used in thin-film solar cells. Such layered structures, also referred to as quasi-2D perovskites, are described by the empirical formula of (LC) 2 (SC) n−1 Pb n I 3n+1 , where LC is a cation with a large ionic radius (usually an aromatic or aliphatic alkyl ammonium halide), SC is a small cation (typically, methylammonium -MA + , or formamidinium -FA + ), and n is the number of confined lead halide octahedral layers. [5] When the perovskite film is processed from a precursor solution, bulky cations organize in a specific way, separating the 3D-like phases, and forming a layered structure. The unique arrangement of the lattice brings certain properties, which can be further tuned with appropriate compositional engineering. [6][7][8] Many compounds of different chain lengths and chemical structures were found to fit the role of the bulky cation. [9,10] Commonly, these large organic cations provide hydrophobic character, enhancing the water resistance of the perovskite layers. [11] The large cation can also passivate various electronic defects in the perovskite structure, and limit ion migration, which in turn provides better photostability. [12] As a result, the quasi-2D perovskites provide an interesting avenue for reaching improved structural robustness and enhanced operational stability when compared to the more conventional 3D counterparts, making them particularly suitable for terrestrial applications. As the large organic cation is electrically insulating, the orientation of perovskite grains needs to be carefully adjusted. In order to enable efficient charge carrier transport through the photoactive layer, low dimensional perovskite sheets need to be oriented perpendicularly to the substrate. [13] Various strategies of inducing preferential vertical alignment of 2D perovskite crystallites have been explored, including coordinating additives, or specific processing conditions, inducing preferential dynamics of the initial crystallization stages. [14,15] Recent advancements in this topic resulted in PCEs exceeding 20%, highlighting the large application potential for these materials. [16] Metal halide perovskites of reduced dimensionality constitute an interesting subcategory of the perovskite semiconductor family, which attract a lot of attention, primarily due to their excellent moisture resistance and peculiar optoelectronic properties. Specifically, quasi-2D materials of the Ruddlesden-Popper (RP) type, are intensely investigated as photoactive layers in perovskite solar cells. Here, a scalable deposition of quasi-2D perovskite thin films, with a nominal composition of 4F-PEA 2 MA 4 Pb 5 I ...

Screen‐Printing Technology for Scale Manufacturing of Perovskite Solar Cells

“…The development goal of perovskite photovoltaic devices is to commercialize with high cost‐effectiveness, which makes fully printing perovskite devices a promising concept. [ 134 , 135 , 136 ] including fully blade coating PSCs, [ 190 ] fully slot‐die coating PSCs, [ 49 , 137 , 138 , 139 ] fully inkjet printing PSCs, [ 140 , 141 ] and fully spray coating PSCs. [ 142 ] Currently, for screen‐printing method, the printing of all functional layers has basically been realized except for perovskite film, because the perovskite precursor solution based on organic solvents is not applicable to screen printing method.…”

Extreme Radiation Resistance of Self‐Powered High‐Performance Cs0.04Rb0.04(FA0.65MA0.35)0.92Pb(I0.85Br0.14Cl0.01)3 Perovskite Photodiodes

“…Hybrid organic-inorganic perovskites possess excellent photoelectric characteristics for high-performance optoelectronics and photovoltaics. [1][2][3][4] Perovskite photodiodes achieve high sensitivity and fast response due to the high mobility and long diffusion length of photo-generated charge carriers coupled with a low exciton binding energy. [5][6][7] Photodiodes have a wide range of applications in diverse fields of science and technology.…”

Large area inkjet-printed metal halide perovskite LEDs enabled by gas flow assisted drying and crystallization

“…The crystallization process can be controlled by temperature, 21,22 vacuum treatment, 23,24 or drying in a gas flow. [25][26][27] We have previously presented a gas flow assisted vacuum drying chamber to achieve precise control over the sample environment after printing and increase the performance of inkjet-printed perovskite solar cells. 28 After initial evacuation of an aluminium chamber, a controlled nitrogen-flow was released in the chamber, which initiated the gas flow assisted drying (GAVD) process of the as-deposited wet film.…”