Reconfiguring the band-edge states of photovoltaic perovskites by conjugated organic cations

Science, Год журнала: 2021, Номер 371(6529), С. 636 - 640

Опубликована: Фев. 4, 2021

A-sites join the band edge The of hybrid organic-inorganic perovskites, which have general formula ABX 3 , is mainly controlled by inorganic X anions (such as chloride) and B cation lead). Organic A-site cations usually only exert indirect structural effects because their electronic levels lie far from edge. Xue et al. show that with large π-conjugated structures can interact frontier molecular orbitals. A surface layer ethylammonium pyrene, had an optimal intercalation distance, increased hole mobilities power conversion efficiencies relative to a reference perovskite also improved device stability. Science this issue p. 636

Язык: Английский

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Halide Perovskites: Thermal Transport and Prospects for Thermoelectricity

Advanced Science, Год журнала: 2020, Номер 7(10)

Опубликована: Апрель 16, 2020

The recent re-emergence of halide perovskites has received escalating interest for optoelectronic applications. In addition to photovoltaics, the multifunctional nature led diverse ultralow thermal conductivity coupled with decent mobility and charge carrier tunability prediction as a possible contender future thermoelectrics. Herein, advances in transport their potentials challenges thermoelectrics are reviewed. An overview phonon behavior perovskites, well compositional dependency is analyzed. Understanding knowing value crucial creating effective heat dissipation schemes determining other thermal-related properties like thermo-optic coefficients, hot-carrier cooling, thermoelectric efficiency. Recent works on perovskite-based together theoretical predictions viability highlighted. Also, progress modulating using light chemical doping discussed. Finally, strategies overcome limiting factors perovskite prospects emphasized.

Язык: Английский

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Soft Lattice and Defect Covalency Rationalize Tolerance of β‐CsPbI₃ Perovskite Solar Cells to Native Defects

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(16), С. 6435 - 6441

Опубликована: Янв. 20, 2020

Although all-inorganic metal halide perovskites (MHPs) have shown tremendous improvement, they are still inferior to the hybrid organic-inorganic MHPs in efficiency. Recently, a conceptually new β-CsPbI3 perovskite reached 18.4 % efficiency combined with good thermodynamic stability at ambient conditions. We use ab initio non-adiabatic molecular dynamics show that native point defects generally benign for nonradiative charge recombination, regardless of whether introduce shallow or deep trap states. These results indicate do not follow simple models used explain defect-mediated recombination conventional semiconductors. The strong tolerance is due softness lattice, which permits separation electrons and holes upon defect formation, only allows carriers couple low-frequency vibrations. Both factors decrease notably coupling slow down dissipation energy heat.

Язык: Английский

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Two-dimensional overdamped fluctuations of the soft perovskite lattice in CsPbBr3

Nature Materials, Год журнала: 2021, Номер 20(7), С. 977 - 983

Опубликована: Март 15, 2021

Язык: Английский

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Efficient Wide-Bandgap Mixed-Cation and Mixed-Halide Perovskite Solar Cells by Vacuum Deposition

ACS Energy Letters, Год журнала: 2021, Номер 6(2), С. 827 - 836

Опубликована: Фев. 3, 2021

Vacuum deposition methods are increasingly applied to the preparation of perovskite films and devices, in view possibility prepare multilayer structures at low temperature. Vacuum-deposited, wide-bandgap solar cells based on mixed-cation mixed-anion perovskites have been scarcely reported, due challenges associated with multiple-source processing thin films. In this work, we describe a four-source vacuum process type FA1–nCsnPb(I1–xBrx)3 tunable bandgap controlled morphology, using FAI, CsI, PbI2, PbBr2 as precursors. The simultaneous sublimation PbI2 allows relative Br/Cs content be decoupled controlled, resulting homogeneous 1.7–1.8 eV range no detectable halide segregation. Solar 1.75 show efficiency up 16.8% promising stability, maintaining 90% initial after 2 weeks operation.

Язык: Английский

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Wide‐Bandgap Perovskite Solar Cell Using a Fluoride‐Assisted Surface Gradient Passivation Strategy

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(11)

Опубликована: Янв. 3, 2023

Wide-band gap (1.68 eV) perovskite solar cells (PSCs) are important components of perovskite/Si tandem devices. However, the efficiency wide band PSCs has been limited by their huge open-circuit voltage (Voc ) deficit due to non-radiative recombination. Deep-level acceptor defects identified as major killers Voc , and they can be effectively improved passivation with ammonium salts. Theoretical calculation predicts that increasing distance between F -NH3+ fluorinated dramatically enhance electropositivity terminals, thus providing strong adsorption onto negatively charged IA IPb anti-site defects. Characterizations further confirm surface gradient employing p-FPEAI demonstrates most efficient effect. Consequently, a record-efficiency 21.63 % smallest 441 mV is achieved for 1.68 eV-band inverted PSCs. Additionally, flexible PSC 1 cm2 opaque device also deliver highest PCEs 21.02 19.31 %, respectively.

Язык: Английский

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The Role of Dimensionality on the Optoelectronic Properties of Oxide and Halide Perovskites, and their Halide Derivatives

Advanced Energy Materials, Год журнала: 2021, Номер 12(4)

Опубликована: Май 5, 2021

Abstract Halide perovskite semiconductors have risen to prominence in photovoltaics and light‐emitting diodes (LEDs), but traditional oxide perovskites, which overcome the stability limitations of their halide counterparts, also recently witnessed a rise potential as solar absorbers. One many important factors underpinning these developments is an understanding role dimensionality on optoelectronic properties and, consequently, performance materials LEDs. This review article examines structural electronic dimensionality, well form factor, lead‐free alternatives perovskites. Insights into how influences band gap, stability, charge‐carrier transport, recombination processes defect tolerance materials, impact parameters device are brought forward. Particular emphasis placed carrier/exciton‐phonon coupling, plays significant considered, owing soft lattices composition heavy elements, becomes more prominent reduced. It finished with discussion implications classes future efforts should focus on, key questions that need be addressed.

Язык: Английский

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Broadband Emission Origin in Metal Halide Perovskites: Are Self‐Trapped Excitons or Ions?

Advanced Materials, Год журнала: 2023, Номер 35(51)

Опубликована: Март 29, 2023

Abstract It has always been a goal to realize high efficiency and broadband emission in single‐component materials. The appearance of metal halide perovskites makes it possible. Their soft lattice characteristics significant electron–phonon coupling synergistically generate self‐trapped excitons (STEs), contributing with large Stokes shift. Meanwhile, their structural/compositional diversity provides suitable active sites coordination environments for doping ns 2 ions, allowing 3 P n ( =0,1,2) → 1 S 0 transitions toward emission. ions is phenomenologically similar that STE emission, hindering in‐depth understanding origin, leading failure meet the design requirements practical applications. In this scenario, herein, fundamentals development such two mechanisms are summarized establish clear comprehensive phenomenon, which may pave way an ideal customization broadband‐emission perovskites.

Язык: Английский

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Passivation strategies for mitigating defect challenges in halide perovskite light-emitting diodes

Joule, Год журнала: 2023, Номер 7(2), С. 272 - 308

Опубликована: Фев. 1, 2023

Язык: Английский

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Electrode Engineering in Halide Perovskite Electronics: Plenty of Room at the Interfaces

Advanced Materials, Год журнала: 2022, Номер 34(18)

Опубликована: Янв. 7, 2022

Contact engineering is a prerequisite for achieving desirable functionality and performance of semiconductor electronics, which particularly critical organic-inorganic hybrid halide perovskites due to their ionic nature highly reactive interfaces. Although the interfaces between charge-transporting layers have attracted lots attention photovoltaic light-emitting diode applications, reliable perovskite/electrode contacts electronic devices, such as transistors memories, remains bottleneck. Herein, review on elusive with focus interfacial electrochemistry effects presented. The basic guidelines electrode selection are given establishing non-polarized optimal energy level alignment perovskite materials. Furthermore, state-of-the-art strategies interface-related reviewed discussed, aim at ohmic transport eliminating hysteresis in devices. role multiple functionalities self-assembled monolayers that offer unique approach toward improving also discussed. insights pave way advancing stable devices diverse applications.

Язык: Английский

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