Antisolvent Additive Engineering for Boosting Performance and Stability of Graded Heterojunction Perovskite Solar Cells Using Amide-Functionalized Graphene Quantum Dots

Abstract

Additive and antisolvent engineering strategies are outstandingly efficient in enhancing perovskite quality, photovoltaic performance, and stability of perovskite solar cells (PSCs). In this work, an effective approach is applied by coupling the antisolvent mixture and multi-functional additive procedures, which is recognized as antisolvent additive engineering (AAE). The graphene quantum dots functionalized with amide (AGQDs), which consists of carbonyl, amine, and long hydrophobic alkyl chain functional groups, are added to the antisolvent mixture of toluene (T) and hexane (H) as an efficient additive to form the CH3NH3PbI3 (MAPI):AGQDs graded heterojunction structure. A broad range of analytical techniques, including scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, space charge limited current, UV–visible spectroscopy, external quantum efficiency, and time-of-flight secondary ion mass spectrometry, are used to investigate the effect of AAE treatment with AGQDs on the quality of perovskite film and performance of the PSCs. Importantly, not only a uniform and dense perovskite film with hydrophobic property is obtained but also defects on the perovskite surface are significantly passivated by the interaction between AGQDs and uncoordinated Pb2+. As a result, an enhanced power conversion efficiency (PCE) of 19.10% is achieved for the champion PSCs treated with AGQD additive, compared to the PCE of 16.00% for untreated reference PSCs. In addition, the high-efficiency PSCs based on AGQDs show high stability and maintain 89% of their initial PCE after 960 h in ambient conditions.

Fluorinated Graphene–Lewis-Base Polymer Composites as a Multifunctional Passivation Layer for High-Performance Perovskite Solar Cells

“…In Figure S8, the original film shows significantly reduced reflection from the main perovskite lattice surface, along with a strong PbI 2 peak at 12.5°, indicating degradation of the perovskite material in the ambient atmosphere. In sharp contrast, PMMA perovskite and FG–PMMA perovskite films are almost completely present in perovskite crystals. , In Figure S9, ITO and Au films sandwiched with perovskites are shown. The conductivity σ can be obtained by the following formula: σ = L / R · S , where S is the common area of ITO and Au, R is the resistance, L is the thickness of perovskite film, and 1/ R · S is obtained from the slope of the curve fitted in Figure S9.…”

“…In sharp contrast, PMMA perovskite and FG−PMMA perovskite films are almost completely present in perovskite crystals. 24,42 In Figure S9, ITO and Au films sandwiched with perovskites are shown. The conductivity σ can be obtained by the following formula: σ = L/R•S, 43 where S is the common area of ITO and Au, R is the resistance, L is the thickness of perovskite film, and 1/R•S is obtained from the slope of the curve fitted in Figure S9.…”

Advances in Structural Modifications and Properties of Graphene Quantum Dots for Biomedical Applications

“…Other key attributes of GQDs are that they are mostly water-soluble or dispersible, are generally biocompatible with human neural cells, have good photostability, and have low cytotoxicity. − The photophysical properties of GQDs include but are not limited to nanosecond luminescence lifetimes and room temperature phosphorescence or white emission . GQDs are amenable to grafting onto other molecules, dyes, metal complexes, or polymers. , This rich chemistry of GQDs is exploited for the design and fabrication of nanodevices for electrocatalysis, electronics, light-emitting diodes, solar cells, , supercapacitors, − and fuel cells. , They also have a high potential for biomedical applications involving diagnosis, drug delivery, gene delivery, − bioimaging, and biosensing . Accordingly, this article focuses on the synthesis, modification, characterization, and biomedical applications of GQDs of size 20 nm or less …”

A Novel Multi‐Functional Thiophene‐Based Organic Cation as Passivation, Crystalline Orientation, and Organic Spacer Agent for Low‐Dimensional 3D/1D Perovskite Solar Cells

“…[1][2][3][4][5][6][7][8][9] On the other hand, their moderate intrinsic stability against moisture and heat still has been a concern with a view on possible commercialization. [10][11][12][13][14] Instability of the 3D methyl ammonium lead iodide (MAPI) perovskite is assumed to be due to its crystalline structure. Ionic migration is now well recognized to affect the photovoltaic properties of perovskite solar cells.…”