Suppression of nonradiative recombination in ionic insulators by defects: Role of fast electron trapping in Tl-doped CsI

Bang, Junhyeok; Wang, Zheming; Gao, Fei; Meng, Sheng; Zhang, Shou-Cheng

doi:10.1103/physrevb.87.205206

Cited by 12 publications

(6 citation statements)

References 37 publications

(37 reference statements)

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“…Our DFT supercell calculations could not localize such small polarons. It is worthwhile to note that self-trapped holes or V k centers are commonly found in insulating alkali- or alkaline-earth halides with calculated binding energies up to several tenths of an eV. − In MAPbI 3 , we find a delocalized hole near VBM is energetically favored over a V k by about 0.1 eV. Similarly, small electron polarons that are stable in cubic structures of Cs 2 LiYCl 6 or Cs 2 HfCl 6 , are unstable in MAPbI 3 .…”

Section: Summary and Conclusionmentioning

confidence: 65%

Preferential CH₃NH₃⁺ Alignment and Octahedral Tilting Affect Charge Localization in Cubic Phase CH₃NH₃PbI₃

Kang

Biswas

2017

J. Phys. Chem. C

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Hybrid organic–inorganic perovskites (CH3NH3PbI3) have gained prominence in recent years due to their fascinating electronic properties and potential for commercial application in photovoltaics and optoelectronics. One of their intriguing features is in the structure itself and the role played by the organic cation CH3NH3 + (MA+). In this study, we implement first-principles-based methods to take a static look at this dynamic system, which may shed some light on the preferential orientation of MA+ and its impact. We find there is a lattice energy gain in cubic CH3NH3PbI3, when going from a pristine host supercell with [100] MA+ orientation to a distorted host consisting of preferentially aligned MA+ and tilted PbI6 octahedra. Reoriented MA+ and octahedral tilting are also accompanied by larger number of (N–H3)···I hydrogen bonds. This lattice reconfiguration may support charge localization as evidenced by larger 216-atom supercell calculations. The localization behavior is a consequence of lattice polarization (reoriented MA+ and tilted octahedra) which spreads across multiple unit cells and thus may not be strongly bound small polarons.

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Section: Summary and Conclusionmentioning

confidence: 65%

Preferential CH₃NH₃⁺ Alignment and Octahedral Tilting Affect Charge Localization in Cubic Phase CH₃NH₃PbI₃

Kang

Biswas

2017

J. Phys. Chem. C

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“…From a physical point of view, the 2H-to-1T′ phase transition is a nonradiative recombination process for the excited carriers, which competes with radiative recombination. As shown in Figure b–d, when the structure evolves due to the phase transition, the excited electron- and hole-occupied gap levels approach each other to facilitate a phonon-mediated carrier recombination , rather than emitting lights. In addition, note that in our calculation a single-layer MoTe 2 is considered.…”

Section: Discussionmentioning

confidence: 99%

Photoinduced Vacancy Ordering and Phase Transition in MoTe₂

et al. 2019

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We show that non-equilibrium dynamics plays a central role in the photoinduced 2H-to-1T′ phase transition of MoTe 2 . The phase transition is initiated by a local ordering of Te vacancies, followed by a 1T′ structural change in the original 2H lattice. The local 1T′ region serves as a seed to gather more vacancies into ordering and subsequently induces a further growth of the 1T′ phase. Remarkably, this process is controlled by photogenerated excited carriers as they enhance vacancy diffusion, increase the speed of vacancy ordering, and are hence vital to the 1T′ phase transition. This mechanism can be contrasted to the current model requiring a collective sliding of a whole Te atomic layer, which is thermodynamically highly unlikely. By uncovering the key roles of photoexcitations, our results may have important implications for finely controlling phase transitions in transition metal dichalcogenides.

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“…For further discussion, we do not exclude other fluorescence quenching possibilities such as X-ray induced defects which may cause non-radiative transitions. [49][50][51] Therefore, both X-ray-induced (Eu 2þ ) þ and defects are possible reasons for the fluorescence quenching of 420 nm emission. The former can reduce the effective Eu 2þ concentration by changing Eu 2þ to (Eu 2þ ) þ while the latter can induce non-radiative procedures, they both can quench the 420 nm defect emission.…”

Section: Discussionmentioning

confidence: 99%

A violet emission in ZnS:Mn,Eu: Luminescence and applications for radiation detection

Jiang

Liu

et al. 2014

Journal of Applied Physics

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Articles you may be interested inTunable emission in surface passivated Mn-ZnS nanophosphors and its application for Glucose sensing AIP Advances 2, 012183 (2012); 10.1063/1.3698310Temperature and pressure behavior of the emission bands from Mn-, Cu-, and Eu-doped ZnS nanocrystalsWe prepared manganese and europium co-doped zinc sulfide (ZnS:Mn,Eu) phosphors and used them for radiation detection. In addition to the red fluorescence at 583 nm due to the d-d transition of Mn ions, an intense violet emission at 420 nm is newly observed in ZnS:Mn,Eu phosphors. The emission is related to Eu 2þ doping but only appears at certain Eu 2þ concentrations. It is found that the intensity of the 420 nm violet fluorescence is X-ray does-dependent, while the red fluorescence of 583 nm is not. The ratio of fluorescence intensities at 420 nm and 583 nm has been monitored as a function of X-ray doses that exposed upon the ZnS:Mn,Eu phosphors. Empirical formulas are provided to estimate the doses of applied X-ray irradiation. Finally, possible mechanisms of X-ray irradiation induced fluorescence quenching are discussed. The intense 420 nm emission not only provides a violet light for solid state lighting but also offers a very sensitive method for radiation detection. V C 2014 AIP Publishing LLC. [http://dx.

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Suppression of nonradiative recombination in ionic insulators by defects: Role of fast electron trapping in Tl-doped CsI

Cited by 12 publications

References 37 publications

Preferential CH₃NH₃⁺ Alignment and Octahedral Tilting Affect Charge Localization in Cubic Phase CH₃NH₃PbI₃

Preferential CH₃NH₃⁺ Alignment and Octahedral Tilting Affect Charge Localization in Cubic Phase CH₃NH₃PbI₃

Photoinduced Vacancy Ordering and Phase Transition in MoTe₂

A violet emission in ZnS:Mn,Eu: Luminescence and applications for radiation detection

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Suppression of nonradiative recombination in ionic insulators by defects: Role of fast electron trapping in Tl-doped CsI

Cited by 12 publications

References 37 publications

Preferential CH3NH3+ Alignment and Octahedral Tilting Affect Charge Localization in Cubic Phase CH3NH3PbI3

Preferential CH3NH3+ Alignment and Octahedral Tilting Affect Charge Localization in Cubic Phase CH3NH3PbI3

Photoinduced Vacancy Ordering and Phase Transition in MoTe2

A violet emission in ZnS:Mn,Eu: Luminescence and applications for radiation detection

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Product

Resources

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Preferential CH₃NH₃⁺ Alignment and Octahedral Tilting Affect Charge Localization in Cubic Phase CH₃NH₃PbI₃

Preferential CH₃NH₃⁺ Alignment and Octahedral Tilting Affect Charge Localization in Cubic Phase CH₃NH₃PbI₃

Photoinduced Vacancy Ordering and Phase Transition in MoTe₂