Suppressing Nickel Oxide/Perovskite Interface Redox Reaction and Defects for Highly Performed and Stable Inverted Perovskite Solar Cells

Abstract

The inorganic hole transport layer of nickel oxide (NiOx) has shown highly efficient, low‐cost, and scalable in perovskite photovoltaics. However, redox reactions at the interface between NiOx and perovskites limit their commercialization. In this study, ABABr (4‐(2‐Aminoethyl) benzoic acid bromide) between the NiOx and different perovskite layers to address the issues has been introduced. How the ABABr interacts with NiOx and perovskites is experimentally and theoretically investigated. These results show that the ABABr molecule chemically reacts with the NiOx via electrostatic attraction on one side, whereas on the other side, it forms a strong hydrogen bond via the NH3+ group with perovskites layers, thus directly diminishing the redox reaction between the NiOx and perovskites layers and passivating the layer surfaces. Additionally, the ABABr interface modification leads to significant improvements in perovskite film morphology, crystallization, and band alignment. The perovskites solar cells (PSCs) based on an ABABr interface modification show power conversion efficiency (PCE) improvement by over 13% and maintain over 90% of its PCE after continuous operation at maximum power point for over 500 h. The work not only contributes to the development of novel interlayers for stable PSCs but also to the understanding of how to prevent interface redox reactions.

Oxysalt based synergistic dual interfacial engineering for high performance p–i–n structured perovskite solar cells

“…These results support that the holes from the photoactive layer can be more effectively extracted and transported towards the anode. 36,39,40…”

“…These results support that the holes from the photoactive layer can be more effectively extracted and transported towards the anode. 36,39,40 The uniformity of the substrate (NiO) typically represents the most important parameter inuencing the lm quality and morphology of spin-coated perovskite lms. The energydispersive X-ray spectroscopy (EDS) mapping images demonstrated the distribution of NaNO 3 on the NiO surface.…”

Dopant‐free NiOx Nanocrystals: A Low‐cost and Stable Hole Transport Material for Commercializing Perovskite Optoelectronics

“…Moreover, we incorporated the Br-BA SAM into the flexible PSCs (F-PSCs) and achieved one of the highest PCE of 16.2 % on the polyethylene terephthalate (PET) substrate with a remarkable power-per-weight of 26.9 W g À 1 . Recently, Choy et al synthesized benzoic acid with a -NH 3 + substituted tail group, namely, 4-(2-aminoethyl) benzoic acid bromide (ABABr), [27] which chemically reacts with the NiO x NCs via electrostatic attraction on one hand and forms a strong hydrogen bond via the -NH 3 + group with perovskites layers, on the other hand, directly diminishing the redox reaction between the NiO x and the perovskites layers and passivating the layer surfaces. Additionally, the ABABr interface modification leads to significant improvements in perovskite film morphology, crystallization, and band alignment.…”

“…[16,17] Recently, an increasing global effort has been invested to advance inverted PSCs, and most of the endeavors have been focused on compositional engineering, [18] additive engineering, [19] processing methods, [20][21][22] and interfacial engineering. [8,[23][24][25][26][27] Although the champion power conversion efficiency (PCE) of inverted PSCs has exceeded 25 %, doped or expensive organic hole transport materials (HTMs), such as poly(bis(4phenyl)(2,4,6-trimethylphenyl)amine) (PTAA) and poly- (3,4-ethylenedioxythiophene) : poly(styrenesulfonate) (PE-DOT : PSS), were initially employed to achieve high performance. Although organic HTMs have been utilized in the highest efficiency of p-i-n structure PSCs, their drawbacks such as high fabrication cost and poor wetting capacity, which hinder their large-scale applications towards commercialization.…”

“…Particularly, advancing inverted (p‐i‐n) PSCs is critical for their commercial applications given their compatibility with different bottom cells for tandem photovoltaics, [11–14] low‐temperature processability (≤100 °C), [15] and promising operational stability [16, 17] . Recently, an increasing global effort has been invested to advance inverted PSCs, and most of the endeavors have been focused on compositional engineering, [18] additive engineering, [19] processing methods, [20–22] and interfacial engineering [8, 23–27] . Although the champion power conversion efficiency (PCE) of inverted PSCs has exceeded 25 %, doped or expensive organic hole transport materials (HTMs), such as poly(bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine) (PTAA) and poly(3,4‐ethylenedioxythiophene) : poly(styrenesulfonate) (PEDOT : PSS), were initially employed to achieve high performance.…”