Aqueous‐Containing Precursor Solutions for Efficient Perovskite Solar Cells

Abstract

Perovskite semiconductors have emerged as competitive candidates for photovoltaic applications due to their exceptional optoelectronic properties. However, the impact of moisture instability on perovskite films is still a key challenge for perovskite devices. While substantial effort is focused on preventing moisture interaction during the fabrication process, it is demonstrated that low moisture sensitivity, enhanced crystallization, and high performance can actually be achieved by exposure to high water content (up to 25 vol%) during fabrication with an aqueous‐containing perovskite precursor. The perovskite solar cells fabricated by this aqueous method show good reproducibility of high efficiency with average power conversion efficiency (PCE) of 18.7% and champion PCE of 20.1% under solar simulation. This study shows that water–perovskite interactions do not necessarily negatively impact the perovskite film preparation process even at the highest efficiencies and that exposure to high contents of water can actually enable humidity tolerance during fabrication in air.

Μethylammonium Chloride: A Key Additive for Highly Efficient, Stable, and Up‐Scalable Perovskite Solar Cells

“…[10][11][12] Even though a debate on the subject was on, researchers kept utilizing the PbCl 2 -based recipe in order to fabricate a good planar solar cell. [17,18] Markedly, in the case of mixed perovskites, we could find only two reports on the addition of PbCl 2 in the precursor CsFAMA solution, resulting in over 21% Lead halide perovskites of the type APbX 3 (where A = methylammonium MA, formamidinium FA, or cesium and X = iodide and bromide), in a singlecrystal form or more often as polycrystalline films, have already shown unique optoelectronic properties, comparable with those of the best singlecrystal semiconductors. [14] Since then, a race has started when a plethora of methods for solution-processed perovskite films have emerged from the combination of MAI with PbI 2 or PbCl 2 in various device architectures.…”

A New Strategy for Increasing the Efficiency of Inverted Perovskite Solar Cells to More than 21%: High‐Humidity Induced Self‐Passivation of Perovskite Films

“…[20][21][22] Water in various forms, such as an additive for precursor solution or moisture in the spin-coating or thermal annealing step, can affect the reaction and crystallization dynamics of perovskite, resulting in favorable changes in the perovskite grain size, crystallinity, and even bulk phase of the perovskite films. [23][24][25][26] However, the underlying mechanism by which the moisture affects the quality of the perovskite film and the device performance is still deficient. [19,21] In this work, we established a new strategy to obtain inverted PSCs with remarkable high V OC by including a high-humidity treatment and sufficient DMSO-atmosphere annealing in the preparation process.…”

Room Temperature Processing of Inorganic Perovskite Films to Enable Flexible Solar Cells

“…Due to the limited solubility of lead halide compounds, the precursor solvents generally chosen are N,N-dimethylformamide (DMF), DMSO, and DMF/DMSO mixtures ( Burschka et al., 2013 , Chen et al., 2016 , Jeon et al., 2014 , Liu et al., 2018a , Liu et al., 2018b , Zhou et al., 2014 ). The solubility of mixed halide cesium lead precursors are particularly limited in DMF ( Figure 1 A) ( Sutton et al., 2016 ), leading some researchers to utilize pure DMSO ( Beal et al., 2016 , Hu et al., 2017 , Li et al., 2017 , Wang et al., 2017c , Zhang et al., 2018a ).…”

“…It can be seen from Figure 1 A that the CsPbI2Br perovskite films can be successfully prepared by the vacuum-assist deposition process under room temperature ( Li et al., 2016 , Liu et al., 2018a , Liu et al., 2018b ). After the NMP solvent was extracted from the film under vacuum, the light brown CsPbI 2 Br perovskite film was formed.…”