Dually‐Passivated Perovskite Solar Cells with Reduced Voltage Loss and Increased Super Oxide Resistance

Abstract

In recent years,t he power conversion efficiency (PCE) of perovskite solar cells (PSCs) has witnessed rapid progress.N evertheless,t he pervasive defects prone to nonradiative recombination and decomposition exist at the surface and the grain boundaries (GBs) of the polycrystalline perovskite films.H erein, we report ac omprehensive dualpassivation (DP) strategy to effectively passivate the defects at both surface and GBs to enhance device performance and stability further.F irstly,afluorinated perylene-tetracarboxylic diimide derivative is permeated in the perovskite metaphase during antisolvent treatment, and then af luorinated bulky aromatic ammonium salt is introduced over the annealed perovskite.T he reduction of defect density can be unambiguously proved by the superoxide species generation/quenching reaction. As ar esult, optimized planar PSCs demonstrate ad ecreased open-circuit voltages deficit from 0.47 to 0.39 V and the best efficiency of 23.80 %from photocurrent scanning with astabilized maximum power output efficiency of 22.99 %. Without encapsulation, one typical device can maintain over 85 %o ft he initial efficiency after heating on ah ot plate at 100 8 8Cf or 30 hu nder relative humidity (RH) of 70 %. When the device is aged under 30 AE 5% RH, over 97 %o fi ts initial PCE is retained after 1700 h.

Two birds with one stone: dual grain-boundary and interface passivation enables >22% efficient inverted methylammonium-free perovskite solar cells

“…16,112,134 We note that we do not observe a peak related to metallic lead (Pb 0 ) at ~137 eV which emphasizes the high quality of our reference perovskite films. 19,20,74,87 Upon PEACl:PbCl 2 incorporation and/or PEACl surface treatment (GBP, SP and GBP&SP films) there are three key observations as compared to the Ref film. Firstly, for BP films the Pb 4f 7/2 core level slightly shifts toward higher binding energies and exhibits an increased FWHM, while for SP and GBP&SP films the signal intensity at ~138.7 eV decreases and the peak becomes broader and asymmetric toward the highenergy side.…”

Two Birds with One Stone: Dual Grain-Boundary and Interface Passivation Enables > 22% Efficient Inverted Methylammonium-Free Perovskite Solar Cells

“…16,112,134 We note that we do not observe a peak related to metallic lead (Pb 0 ) at B137 eV which emphasizes the high quality of our reference perovskite films. 19,20,74,87 Upon PEACl:PbCl 2 incorporation and/or PEACl surface treatment (GBP, SP and GBP&SP films) there are three key observations as compared to the Ref film. Firstly, for BP films the Pb 4f 7/2 core level slightly shifts toward higher binding energies and exhibits an increased FWHM, while for SP and GBP&SP films the signal intensity at B138.7 eV decreases and the peak becomes broader and asymmetric toward the highenergy side.…”

“…49,[52][53][54][55][56][57][58] Prominent examples for tailored passivation schemes are the use of (alkyl)ammonium salts, 3,4,6,10,11,13,14,20,22, other organic compounds 16,19,24,45,[81][82][83][84][85][86][87] and fluoride-containing materials. 31,35,38,74,86,88,89 Alongside established chemical passivation that reduces the density of surface/interface defects, 53,63,83,85 this strategy also encompasses performance enhancements by the formation of 2D/3D heterostructures 10,[59][60][61]63,64,70,[76][77][78] and/or wide-bandgap interface layers.…”

“…31,35,38,88,89,93 However, PSCs with LiF undergo severe long-term degradation which limits the applicability of this approach. 31,93 In order to reduce non-radiative recombination in the bulk and grain boundaries, the use of non-stoichiometric precursors [94][95][96] or incorporation of different additives into the perovskite precursor solution or antisolvent such as metal cations, 97 anions, 98 chloride (Cl) or thiocyanate (SCN), [4][5][6]10,14,15,17,19,88 (alkyl)ammonium salts, 3,25,26,64,[98][99][100][101][102][103][104][105] other organic compounds, 74,84,106 and fluoride-containing materials 74,107 have been proposed. Given that these additives directly assist in perovskite film formation, changes in crystallization dynamics as well as a reduced defect density are commonly observed.…”

Thermal‐Triggered Dynamic Disulfide Bond Self‐Heals Inorganic Perovskite Solar Cells

“…[1][2][3][4] Despite great advances in the PCE, the inferior long-term stability under persistent light, humidity and/or heat attacks is still a big burden for their commercialization [5][6][7] because of the inevitable phase decomposition, chemical bond rupture, and formation of detrimental species. [8,9] Although a few of the strategies including additives and interfacial regulation stabilize the perovskite lattices, [10,11] the perovskite films can only withstand limited stimuli in real use. As a result, irreversible performance degradation happens upon the depletion of the initial optimization effect to cause a reduced shelf-life.…”