Multidentate Coordination Induced Crystal Growth Regulation and Trap Passivation Enables over 24% Efficiency in Perovskite Solar Cells

Abstract

The solutionprocessed perovskite is mostly polycrystalline with a large number of grain boundaries (GBs) that induce the fastest ion migration than other sites. [5][6][7][8][9] Meanwhile, the GBs are the dominating attack sites of water and oxygen, which will deteriorate the operation stability of PerSCs. [10][11][12][13][14] Therefore, high-grade perovskite films with high coverage, ideal crystal morphology, good crystallinity, and few defects are crucial for fabricating high-performance PerSCs. [15,16] Plentiful reports have shown that introducing functional additives into perovskite precursor solution can affect the nucleation rate, film morphology, grain size, and crystallinity of perovskite. Precursor additives, such as dimethyl sulfoxide, acids or 2D perovskite, play a vital role in the film formation of perovskite, determining the photovoltaic performance of PerSCs. [17][18][19][20][21] In 2015, Yan et al. revealed that the precursor of MAPbI 3 is a colloid state rather than a real solution. The addition of methylammonium iodide and methylamine chloride leads to a facilitated aggregation of lead iodide, which effectively improves the crystallinity of the perovskite film and ultimately yields promoted PCEs in PerSCs. [22] Ran et al. found that PbI 2 colloid has a wider particle size distribution and larger colloid under certain acidic conditions. [23] Liang et al. proposed an effective cosolvent strategy by introducing ethyl alcohol into the perovskite ink to construct high-performance, blade-coated PerSC modules. [4] Furthermore, the latest reports shed new light on controlling crystallization in 2D perovskites. A 2D (NpMA) 2 PbI 4 perovskite was incorporated into the PbI 2 precursor to modify the crystal growth process in 2D/3D perovskite film using a two-step deposition method. [24] Luo and his coworkers introduced highly oriented 2D (BDA)PbI 4 perovskites as seeds to chalk up large size colloids, which can optimize the growth kinetics of 3D perovskite and make its crystallization directly stride over the nucleation stage. [25] The introduction of these crystal auxiliary components has been proved to be a practical approach to modifying the grain size of perovskite films, while a synergistic function in inhibiting the formation of GBs Crystal growth regulation has become an effective solution to reduce the defects at grain boundaries (GBs) and surfaces of perovskite films for better photovoltaic performances. Oxime acid materials are maturely used as selective collectors in the flotation separation of oxide minerals. Such materials, showing a strong coordination effect and high selectivity with lead, may have great potential in controlling the crystal growth and passivating the defect of perovskite film, which are rarely applied in perovskite solar cells (PerSCs). Herein, an oxime acid-based material with multi-coordination sites, ethyl 2-(2-aminothiazole-4-yl)-2-hydroxyiminoacetate (EHA), is incorporated into the PbI 2 precursor solution to fabricate high-performance PerSCs using a two-step method. The ...

Solvent bath annealing-induced liquid phase Ostwald ripening enabling efficient and stable perovskite solar cells

“…Typically, perovskite dissolution occurs through the formation of a perovskite-solvent complex with coordination bonds. 37,38 Therefore, strong chemical interactions between solvent molecules and perovskite materials are vital to the Ostwald ripening process. [39][40][41] The SBA process uses similar polar solvents to that used in SVA, but the nonpolar solvent (CB) serves as a liquid medium to support mass transport.…”

Simultaneous Interface Amelioration and Energy Level Modulation Using In Situ Polymerized Molecules for Efficient and Stable Perovskite Solar Cells

“…Expectedly, the MAPS-dimer-decorated device increases the photovoltaic performance to achieve a J sc of 22.93 mA cm –2 , a V oc of 1.11 V, and a FF of 0.781, resulting in a favorable efficiency of 19.88%. Associated with the SEM analysis of perovskite films, it is universally acknowledged that high-density defects distributing along perovskite GBs and interfaces can seriously deteriorate the optoelectronic properties of PSCs. , In contrast, the better crystal quality and fewer GBs together with larger perovskite grains herein with the assistance of MAPS monomers and MAPS dimers can significantly decrease defect-assisted nonradiative recombination and promote the V oc of the devices . Modified charge transport and suitable surface ELA facilitate significant increments for the FF values of the optimized PSCs.…”

Chemical Chelation-Assisted Highly Oriented Perovskite Solar Cells with Reduced Non-radiative Loss

“…The addition of additives containing various functional groups (such as carbonyl, sulfonic, amino, halogens, etc.) to perovskite films is a promising strategy for regulating the crystallization of perovskite to obtain high-quality films and minimize the formation of defects. − An additive interacts with the perovskite components through electrostatic force to regulate the crystallization of perovskite films and passivate defects on the surface and at grain boundaries of perovskite films . The most common strategy is to introduce additives into the precursor solution.…”