Materials and Cavity Design Principles for Exciton-Polariton Condensates

ACS Nano, Год журнала: 2025, Номер unknown

Опубликована: Март 10, 2025

Exciton-polariton condensation offers a promising path to low-threshold coherent light sources, impacting fields from communications healthcare. These hybrid quasiparticles, arising strong exciton-photon coupling, combine the low effective mass their photonic component and nonlinear interactions excitons. While polariton has been achieved in range of inorganic organic materials, many systems still face significant challenges despite fulfilling main properties requirements. In this perspective, we examine mechanisms across different materials highlight that universal guidelines do not exist; instead, believe exciton-polariton is governed by intrinsic active material. We propose using 2D perovskites as versatile platforms investigate how specific structural electronic characteristics influence processes driving condensation. By exploiting versatility perovskites, can systematically explore establish principles guiding realization various material systems.

Язык: Английский

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Luminescence From Localized States in Solids: A First‐Principles Perspective

Advanced Functional Materials, Год журнала: 2025, Номер unknown

Опубликована: Март 3, 2025

Abstract Localized‐state luminescence (LSL) has emerged as a promising mechanism for high‐performance optoelectronic applications, including lighting, photodetection, and quantum technologies. Characterized by rich intriguing spectral features, LSL involves significant electron‐phonon coupling, which varies in strength across different systems. First‐principles methods, particularly density functional theory (DFT) its extensions provide an efficient framework modeling the process with reasonable accuracy. This comprehensive review examines DFT‐based studies on three representative types of solids: from self‐trapped excitons (STEs), normal defects, intentionally doped ions. The discussion begins overview entire process, highlighting computational methods excited state structures energies, well simulations luminescent spectrum within multi‐phonon transition framework. Detailed discussions follow, focusing structural distortion modes STEs, behavior mechanisms Finally, strategies to address current challenges advance theoretical design materials are proposed, offering valuable insights future developments field.

Язык: Английский

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Validation of the GreenX library time-frequency component for efficient GW and RPA calculations

Physical review. B./Physical review. B, Год журнала: 2024, Номер 109(24)

Опубликована: Июнь 3, 2024

Electronic structure calculations based on many-body perturbation theory [e.g., GW or the random-phase approximation (RPA)] require function evaluations in complex time and frequency domain, for example, inhomogeneous Fourier transforms analytic continuation from imaginary axis to real axis. For transforms, time-frequency component of GreenX library provides grids that can be utilized low-scaling RPA implementations. In addition, adoption compact provided by our also reduces computational overhead implementations with conventional scaling. this paper, we present benchmark using different codes (FHI-aims, CP2K, ABINIT) molecules, two-dimensional materials solids. Very small integration errors are observed when 30 points test cases, namely $<{10}^{\ensuremath{-}8}$ eV/electron correlation energies, $\ensuremath{\le}10$ meV $GW$ quasiparticle energies.

Язык: Английский

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Exciton Transport in Perovskite Materials

Advanced Materials, Год журнала: 2024, Номер unknown

Опубликована: Дек. 30, 2024

Halide perovskites have emerged as promising materials for a wide variety of optoelectronic applications, including solar cells, light-emitting devices, photodetectors, and quantum information applications. In addition to their desirable optical electronic properties, halide provide tremendous synthetic flexibility through variation not only chemical composition but also structure morphology. At the heart use in technologies is interaction light with excitations form excitons. This review discusses properties behavior excitons perovskite materials, particular emphasis on low-dimensional effects nanoscale morphology excitonic behavior. The basic theory energy migration semiconductor nanomaterials introduced, novel observations that evolved our current understanding are explored. Finally, many important questions remain unanswered presented exciting emerging directions exciton physics discussed.

Язык: Английский

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Three-Dimensional to Layered Halide Perovskites: A Parameter-Free Hybrid Functional Method for Predicting Electronic Band Gaps

ACS Materials Letters, Год журнала: 2025, Номер unknown, С. 1922 - 1929

Опубликована: Апрель 17, 2025

Язык: Английский

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Performance of the Bethe–Salpeter Equation for Electronic Excitations in First-Row Transition Metal Complexes

Journal of Chemical Theory and Computation, Год журнала: 2025, Номер unknown

Опубликована: Апрель 28, 2025

The performance of the Green's function-Bethe-Salpeter Equation (BSE@GW) approach has been systematically tested on a series first-row transition metal complexes. Special attention was paid to interplay between metal-centered (MC) and charge transfer (CT) transitions their ordering in excited singlet triplet state manifolds. Here, commonly used time-dependent density functional theory (DFT) reaches its limits particular shows strong dependence exchange-correlation functional. In contrast, present BSE@GW ultraviolet-visible (UV-vis) spectra show good agreement with experimental results as far absorption assignment are concerned. This is achieved independently underlying initial guess GW iteration. These conclusions drawn basis an investigation test set including nearly pure MC triazacyclononane different centers mixed MC-CT Fe(II) complexes numbers N-heterocyclic carbene ligands. Furthermore, important aspects calculations such ground equilibrium geometry or influence Tamm-Dancoff approximation highlighted.

Язык: Английский

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BA₂SnI₄ as a Promising 2D Ruddlesden–Popper Perovskite for Optoelectronic Applications

The Journal of Physical Chemistry C, Год журнала: 2025, Номер unknown

Опубликована: Май 18, 2025

Язык: Английский

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Halide perovskites from first principles: from fundamental optoelectronic properties to the impact of structural and chemical heterogeneity

Electronic Structure, Год журнала: 2024, Номер 6(3), С. 033002 - 033002

Опубликована: Июнь 14, 2024

Abstract Organic-inorganic metal-halide perovskite semiconductors have outstanding and widely tunable optoelectronic properties suited for a broad variety of applications. First-principles numerical modelling techniques are playing key role in unravelling structure-property relationships this structurally chemically diverse family materials, predicting new materials properties. Herein we review first-principles calculations the photophysics halide perovskites with focus on band structures, optical absorption spectra excitons, effects electron- exciton-phonon coupling temperature these We approaches based density functional theory Green’s function-based many-body perturbation provide an overview approaches. While large proportion studies been focusing prototypical ABX 3 single Pb Sn, recent years witnessed significant efforts to further functionalize perovskites, broadening include double quasi-low-dimensional other organic-inorganic interfaces heterostructures. enormous chemical space perovskite-like has only begun be tapped experimentally, advances theoretical computational methods, as well computing infrastructure, led possibility understanding ever more complex systems. illustrate progress our by summarizing representative various degrees complexity.

Язык: Английский

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Geometric and electronic structures of Cs2BB′X6 double perovskites: The importance of exact exchange

Physical Review Research, Год журнала: 2024, Номер 6(3)

Опубликована: Авг. 14, 2024

A widely adopted computational protocol in contemporary materials research is to first relax materials' geometries using semilocal density functional approximations (DFA), and then determining their electronic band structures the more expensive hybrid functionals. This procedure often works well, as popular DFAs, such Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation, yield rather good for a wide range of materials. However, here we show that, some lead-free halide double perovskites (HDPs) Cs2BB′X6 (B=Ag+, Na+; B′=In3+, Bi3+; X=Cl−, Br−), validity this common practice questionable. We find these HDPs, geometrical structures, particular, B(B′)−X bond lengths predicted by PBE large deviations from experimental values. Additionally, gaps (specifically, In-based HDPs) are sensitive B(B′)−X lengths. As consequence, obtained functionals (such Heyd-Scuseria-Ernzerhof functional) based on can still be quite off, HDPs with B′=In3+. The situation significantly improved tuned portion exact exchange, determined consistently under same level theory. successes failures several exchange-correlation (XC) traced back so-called delocalization error, quantitatively analyzed understood via three-atom linear-chain B−X−B′ molecular model. Finally, our findings provide practical guide choosing appropriate XC describing point promising path structure engineering doping alloying. Published American Physical Society 2024

Язык: Английский

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Halide Mixing in Cs₂AgBi(I_xBr_1–x)₆ Double Perovskites: A Pathway to Tunable Excitonic Properties

The Journal of Physical Chemistry C, Год журнала: 2024, Номер 128(35), С. 14767 - 14775

Опубликована: Авг. 26, 2024

Cs2AgBiBr6 is an emerging double perovskite semiconductor with robust stability. However, its potential for photovoltaics limited by indirect band gap and localized electronic structure featuring a resonant exciton large binding energy. Cs2AgBi(IxBr1–x)6 nanocrystals iodide concentrations of up to 100% were recently demonstrated, but atomistic understanding how halide mixing affects the excited-state missing. Here, we use first-principles GW Bethe–Salpeter Equation calculations show that leads pronounced change in character optical excitations. Exciton energies are reduced factor 5, significantly more delocalized excitons I-rich compounds. We further phase-pure bulk alloys x ≤ 0.11 can be fabricated using mechanosynthesis measure red-shifted absorption line our calculations. Our study highlights perovskites not only lead significant changes may also used tuning excitonic properties.

Язык: Английский

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