1,721,053 research outputs found
Efficient, Stable and Scalable Perovskite Solar Cells
No full textSince 2009, power conversion efficiencies (PCE) of perovskite solar cells (PSCs) has been rising from the initial 3.8% to the state-of-the-art 25.7% within over the past 10 years. Most highly efficient PSCs utilize an n-type layer of mesoporous titanium dioxide or tin oxide in an n-i-p device configuration, in which organic conductors are widely used to transport holes into an adjoined metal. Thus far, a variety of efforts have been devoted to achieve a defect-less perovskite film with high-quality morphologies for realizing reduced loss-in-potential outcomes and enhanced efficiency levels. As a result, these holistic advancements in interface engineering, composition engineering, and charge-transporting layer engineering for perovskite solar cells enable us to achieve a PCE of over 25%. In this talk, I will briefly introduce our recent advances and understanding of the limitation to improving the photovoltaic performance further (Nature 2021, 590, 587; ACS Energy Lett. 2022, 7, 2084). In particular, I will focus on talking about molecular engineering of interface modifiers and charge-transporting layers for enhancing both efficiency and stability of perovskite solar cells (Adv. Energy Mater. 2022, 12, 2200758). Finally, I will review our efforts to realize scale-up of PSCs toward practical applications (Energy & Environ. Sci. 2020, 13, 4854; Nature Comm. 2020, 11, 5146)
Molecular Engineering of Interface Modifiers for Efficient and Stable Perovskite Solar Cells
No full textSince 2009, power conversion efficiencies (PCE) of perovskite solar cells (PSCs) has been rising from the initial 3.8% to the state-of-the-art 25.7% within over the past 10 years. Most highly efficient PSCs utilize an n-type layer of mesoporous titanium dioxide or tin oxide in an n-i-p device configuration, in which organic conductors are widely used to transport holes into an adjoined metal. Thus far, a variety of efforts have been devoted to achieve a defect-less perovskite film with high-quality morphologies for realizing reduced loss-in-potential outcomes and enhanced efficiency levels. As a result, these holistic advancements in interface engineering, composition engineering, and charge-transporting layer engineering for perovskite solar cells enable us to achieve a PCE of over 25%. In this talk, I will briefly introduce our recent advances and understanding of the limitation to improving the photovoltaic performance further.[1,2] In particular, I will focus on talking about molecular engineering of interface modifiers and charge-transporting layers for enhancing both efficiency and stability of perovskite solar cells.[3
Molecular engineering of interface modifier for efficient and stable perovskite solar cells
No full textPower conversion efficiencies (PCE) of perovskite solar cells (PSCs) has rising from the initial 3.8% to the state-of-the-art 25.7% within the past few years. Most highly efficient PSCs utilize an n-type layer of mesoporous titanium dioxide or tin oxide in an n-i-p device configuration, in which organic conductors are widely used to transport holes into an adjoined metal. Thus far, a variety of efforts have been devoted to achieve a defect-less perovskite film with high-quality morphologies for realizing reduced loss-in-potential outcomes and enhanced efficiency levels. To ensure both efficiency and stability of perovskite solar cells, we suggested a rational interface design at the interface of the perovskite and the HTM that would lead to the effective passivation of surface defects, a favorable energy-level alignment for facilitating hole extraction, and robust interfacial contact against an environmental stimulus. Through full optimization by adopting function-tailored interface modifier (IM), the champion cell exhibited a PCE of 23.6% under forward scan and a stabilized PCE of 23.1% under MPPT. Stabilized interface with IM and PTAA led to excellent thermal and operational stability for more than 1000 hrs. We expect that our strategy of rational interface design in efficient and stable PSCs will greatly contribute to commercialization in the future
Functionalized Polymer-Capped SnO2 Nanoparticle Electron Transport Layer for Efficient Perovskite Solar Cells
No full textFor the last decade, perovskite solar cells have been in rapid growth, highlighted as a representative next-generation solar cell. Although SnO2 is suitable as the electron-transporting material of perovskite solar cells, there also have been some obstacles in the formation of uniform and thin layers of SnO2 on the uneven FTO substrate. In this work, we investigated polymer-assisted fabrication methods to achieve conformal coating of SnO2 nanoparticles on rough FTO substrate, finally leading to improved performance of perovskite solar cells due to enhanced coverage and optimized electron-transporting property. As a result, we fabricated an efficient perovskite solar cells with a power conversion efficiency of 24% by employing polymer-capped SnO2 nanoparticles as electron-transporting layer.
Torsion-induced fluorescence quenching in excited-state intramolecular proton transfer (ESIPT) dyes
No full textFluorescence quenching behaviors of four known excited-state intramolecular proton transfer (ESIPT) molecules have been studied by semiempirical and ab initio calculations. The ESIPT compounds studied in this work are assorted into two sets depending on the N-containing ring structure (5- and 6-membered rings). It has been found that twisted intramolecular charge transfer (TICT) process in the excited keto state (K*) after ESIPT, one of the possible quenching pathways of ESIPT fluorescence, is significantly influenced by the geometrical properties of intramolecular hydrogen (H) bond associated with the N-containing ring structure. The compounds with 5-membered ring have efficient ESIPT emission with large barrier to fluorescence-quenching TICT state, due to appropriate stabilization of planar K* through intramolecular H bond. For the compounds with 6-membered ring, however, ESIPT emission is completely quenched due to significantly lowered barrier resulting from too short H-bond length. The effect of intramolecular H bond on the TICT reaction potential has been discussed in detail from the viewpoints of molecular structure and torsional motion, with the help of elaborate model compound studies. (c) 2007 Elsevier B.V. All rights reserved.
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