Antisolvent Additive Engineering Containing Dual-Function Additive for Triple-Cation p–i–n Perovskite Solar Cells with over 20% PCE

Abstract

In this work, we attempt to improve the quality of the perovskite film using a functional additive in the perovskite antisolvent, which is known as antisolvent additive engineering (AAE). An AAE additive, 2-hydroxyethyl acrylate (HEA), that includes −OH and CO functional groups is introduced into the antisolvent. Its effect on the perovskite film and devices is then systematically studied. Comprehensive analyses including cell performance, carrier transport dynamics, and perovskite surface and morphology measurements were performed to prove that this HEA-based AAE leads to better perovskite films with a larger grain size and fewer perovskite defects and also to prove that this AAE approach is a promising way to obtain high-quality perovskite and corresponding high-efficiency perovskite solar cells. As a result, this facile AAE with HEA obtained a maximum power conversion efficiency (PCE) of 20.46% and showed better stability, maintaining over 61% of its initial PCE after 96 days under ambient air conditions.

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

“…Perovskite films fabricated via traditional solution process are prone to produce defects at the surfaces and GBs, which serve as non‐radiative recombination centers leading to an overall reduction of efficiencies and poor stability of the device [10] . The chemical passivation of those defects can be rationalized into two main strategies: i. mixing additive substances in the precursor solutions [11, 12] or antisolvents [13–16] to control perovskite growth and/or passivate defects in perovskite GBs; ii. surface modification via coating functional molecules on the preformed perovskite layer.…”

“…Firstly, a solution of conjugated N, N′‐bis‐(7,7,8,8,9,9,10,10,11,11,12,12,12‐tridecafluoro dodecan‐5‐yl)‐perylene‐3,4,9,10‐tetracarboxylic diimide (FPD) in chlorobenzene (CB) is used as the antisolvent (anti‐solution), to implant the FPD inside the film during the nucleation of perovskites. This protocol ensures that the defects (e.g., noncoordinating Pb 2+ ) at GBs be passivated by the carbonyl groups (C=O), and the fluorine atoms can form hydrogen bonds with MA + to immobilize the cations, thus ensuring thermal stability [13–15, 35] . Secondly, a hydrophobic 2D perovskite layer is formed in situ on the 3D perovskite layer by successively depositing 2‐(2‐Fluorophenyl)ethylamine iodide after the antisolvent‐treatment to passivate the defects on the surface.…”

Long-Term Stability Analysis of 3D and 2D/3D Hybrid Perovskite Solar Cells Using Electrochemical Impedance Spectroscopy

“…Numerous studies have been performed to overcome the instability issues associated with perovskite materials. There have been attempts to modify three-dimensional (3D) perovskite by using additives [ 6 ], introducing intermediate phases [ 7 ], encapsulating the layers [ 8 ], etc. Several studies have been dedicated to analyzing the effect of mixed cations and halides to enhance PSCs’ stability and efficiency.…”

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

“…[10] Thechemical passivation of those defects can be rationalized into two main strategies:i . mixing additive substances in the precursor solutions [11,12] or antisolvents [13][14][15][16] to control perovskite growth and/or passivate defects in perovskite GBs;i i. surface modification via coating functional molecules on the preformed perovskite layer. Va rious organic molecules [17][18][19][20] and polymers [21][22][23][24] have been applied to chemically passivate the defects on the perovskite surface in PSCs.…”

“…[33,34] In this context, we introduce ac omprehensive dualpassivation (DP) strategy to realize the passivation of defects both inside the GBs and over the surface.Firstly,asolution of conjugated N, N'-bis- (7,7,8,8,9,9,10,10,11,11,12,12,12-tridecafluoro dodecan-5-yl)-perylene-3,4,9,10-tetracarboxylic diimide (FPD) in chlorobenzene (CB) is used as the antisolvent (anti-solution), to implant the FPD inside the film during the nucleation of perovskites.T his protocol ensures that the defects (e.g.,n oncoordinating Pb 2+ )a tG Bs be passivated by the carbonyl groups (C=O), and the fluorine atoms can form hydrogen bonds with MA + to immobilize the cations,t hus ensuring thermal stability. [13][14][15]35] Secondly,ahydrophobic 2D perovskite layer is formed in situ on the 3D perovskite layer by successively depositing 2-(2-Fluorophenyl)ethylamine iodide after the antisolvent-treatment to passivate the defects on the surface.A sar esult, the novel DP strategy prolongs carrier lifetime through defect passivation and, hence,lifts the V OC from 1.10 Vt o1 .18 V, corresponding to a V OC deficit of 0.39 V. In the complete devices,w ea chieved ac hampion stabilized PCE as high as 23.80 %. It is found that besides the excellent thermal and moisture resistant properties [9,14,18,33,36,37] provided by the DP strategy,t he effective passivation of site-vacancy-type defects (e.g., iodine vacancy) successfully suppressed the generation of O 2 À species.E specially,t his is the first time to observe the decrease of destructive O 2 À species by forming a2 Dp erovskite layer.…”