Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Tuning trion binding energy and oscillator strength in a laterally finite 2D system: CdSe nanoplatelets as a model system for trion properties.
Nanoscale ( IF 6.7 ) Pub Date : 2020-06-22 , DOI: 10.1039/d0nr03170d Sabrine Ayari 1 , Michael T Quick 2 , Nina Owschimikow 2 , Sotirios Christodoulou 3 , Guillaume H V Bertrand 4 , Mikhail Artemyev 5 , Iwan Moreels 6 , Ulrike Woggon 2 , Sihem Jaziri 7 , Alexander W Achtstein 2
Nanoscale ( IF 6.7 ) Pub Date : 2020-06-22 , DOI: 10.1039/d0nr03170d Sabrine Ayari 1 , Michael T Quick 2 , Nina Owschimikow 2 , Sotirios Christodoulou 3 , Guillaume H V Bertrand 4 , Mikhail Artemyev 5 , Iwan Moreels 6 , Ulrike Woggon 2 , Sihem Jaziri 7 , Alexander W Achtstein 2
Affiliation
We present a theoretical study combined with experimental validations demonstrating that CdSe nanoplatelets are a model system to investigate the tunability of trions and excitons in laterally finite 2D semiconductors. Our results show that the trion binding energy can be tuned from 36 meV to 18 meV with the lateral size and decreasing aspect ratio, while the oscillator strength ratio of trions to excitons decreases. In contrast to conventional quantum dots, the trion oscillator strength in a nanoplatelet at low temperature is smaller than that of the exciton. The trion and exciton Bohr radii become lateral size tunable, e.g. from ∼3.5 to 4.8 nm for the trion. We show that dielectric screening has strong impact on these properties. By theoretical modeling of transition energies, binding energies and oscillator strength of trions and excitons and comparison with experimental findings, we demonstrate that these properties are lateral size and aspect ratio tunable and can be engineered by dielectric confinement, allowing to suppress e.g. detrimental trion emission in devices. Our results strongly impact further in-depth studies, as the demonstrated lateral size tunable trion and exciton manifold is expected to influence properties like gain mechanisms, lasing, quantum efficiency and transport even at room temperature due to the high and tunable trion binding energies.
中文翻译:
在横向有限的2D系统中调整Trion的结合能和振荡器强度:CdSe纳米片作为Trion特性的模型系统。
我们目前进行的一项理论研究与实验验证相结合,证明CdSe纳米片是一个模型系统,用于研究横向有限二维半导体中tri和激子的可调谐性。我们的结果表明,随着横向尺寸和纵横比的减小,三重子的结合能可以从36 meV调节到18 meV,而三重子与激子的振子强度比则减小。与传统的量子点相反,纳米片中低温下的Trion振荡器强度小于激子。三重子和激子玻尔半径变为侧向尺寸可调,例如对于三光子,从〜3.5到4.8 nm。我们证明介电屏蔽对这些特性有很强的影响。通过理论上的过渡能,束缚能和tri子和激子的振子强度的理论建模以及与实验结果的比较,我们证明了这些特性是横向尺寸和纵横比可调的,并且可以通过介电限制进行工程设计,从而可以抑制例如有害的tri子发射。设备。我们的结果极大地影响了进一步的深入研究,因为已证实的横向尺寸可调谐tri子和激子流形由于高和可调谐的tri子结合能而有望影响诸如增益机制,激射,量子效率和传输等性质,即使在室温下也是如此。
更新日期:2020-07-16
中文翻译:
在横向有限的2D系统中调整Trion的结合能和振荡器强度:CdSe纳米片作为Trion特性的模型系统。
我们目前进行的一项理论研究与实验验证相结合,证明CdSe纳米片是一个模型系统,用于研究横向有限二维半导体中tri和激子的可调谐性。我们的结果表明,随着横向尺寸和纵横比的减小,三重子的结合能可以从36 meV调节到18 meV,而三重子与激子的振子强度比则减小。与传统的量子点相反,纳米片中低温下的Trion振荡器强度小于激子。三重子和激子玻尔半径变为侧向尺寸可调,例如对于三光子,从〜3.5到4.8 nm。我们证明介电屏蔽对这些特性有很强的影响。通过理论上的过渡能,束缚能和tri子和激子的振子强度的理论建模以及与实验结果的比较,我们证明了这些特性是横向尺寸和纵横比可调的,并且可以通过介电限制进行工程设计,从而可以抑制例如有害的tri子发射。设备。我们的结果极大地影响了进一步的深入研究,因为已证实的横向尺寸可调谐tri子和激子流形由于高和可调谐的tri子结合能而有望影响诸如增益机制,激射,量子效率和传输等性质,即使在室温下也是如此。