scholarly journals Structurally Tunable Two-Dimensional Layered Perovskites: From Confinement and Enhanced Charge Transport to Prolonged Hot Carrier Cooling Dynamics

2020 ◽  
Vol 11 (14) ◽  
pp. 5705-5718 ◽  
Author(s):  
Ala’a O. El-Ballouli ◽  
Osman M. Bakr ◽  
Omar F. Mohammed
2020 ◽  
Vol 8 (47) ◽  
pp. 25402-25410
Author(s):  
Dabin Lin ◽  
Lin Ma ◽  
Wenjun Ni ◽  
Cheng Wang ◽  
Fangteng Zhang ◽  
...  

Ultrafast sub-ps hot carrier relaxation followed by subsequent ps carrier transport from layered 2D to 3D-like perovskite phases is demonstrated.


2019 ◽  
Author(s):  
Simil Thomas ◽  
Hong Li ◽  
Raghunath R. Dasari ◽  
Austin Evans ◽  
William Dichtel ◽  
...  

<p>We have considered three two-dimensional (2D) π-conjugated polymer networks (i.e., covalent organic frameworks, COFs) materials based on pyrene, porphyrin, and zinc-porphyrin cores connected <i>via</i> diacetylenic linkers. Their electronic structures, investigated at the density functional theory global-hybrid level, are indicative of valence and conduction bands that have large widths, ranging between 1 and 2 eV. Using a molecular approach to derive the electronic couplings between adjacent core units and the electron-vibration couplings, the three π-conjugated 2D COFs are predicted to have ambipolar charge-transport characteristics with electron and hole mobilities in the range of 65-95 cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup>. Such predicted values rank these 2D COFs among the highest-mobility organic semiconductors. In addition, we have synthesized the zinc-porphyrin based 2D COF and carried out structural characterization via powder X-ray diffraction and surface area analysis, which demonstrates the feasability of these electroactive networks.</p>


Author(s):  
Sai Manoj Gali ◽  
David Beljonne

Transition Metal Dichalcogenides (TMDCs) are emerging as promising two-dimensional (2D) materials. Yet, TMDCs are prone to inherent defects such as chalcogen vacancies, which are detrimental to charge transport. Passivation of...


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jun Yin ◽  
Rounak Naphade ◽  
Partha Maity ◽  
Luis Gutiérrez-Arzaluz ◽  
Dhaifallah Almalawi ◽  
...  

AbstractHot-carrier cooling processes of perovskite materials are typically described by a single parabolic band model that includes the effects of carrier-phonon scattering, hot phonon bottleneck, and Auger heating. However, little is known (if anything) about the cooling processes in which the spin-degenerate parabolic band splits into two spin-polarized bands, i.e., the Rashba band splitting effect. Here, we investigated the hot-carrier cooling processes for two slightly different compositions of two-dimensional Dion–Jacobson hybrid perovskites, namely, (3AMP)PbI4 and (4AMP)PbI4 (3AMP = 3-(aminomethyl)piperidinium; 4AMP = 4-(aminomethyl)piperidinium), using a combination of ultrafast transient absorption spectroscopy and first-principles calculations. In (4AMP)PbI4, upon Rashba band splitting, the spin-dependent scattering of hot electrons is responsible for accelerating hot-carrier cooling at longer delays. Importantly, the hot-carrier cooling of (4AMP)PbI4 can be extended by manipulating the spin state of the hot carriers. Our findings suggest a new approach for prolonging hot-carrier cooling in hybrid perovskites, which is conducive to further improving the performance of hot-carrier-based optoelectronic and spintronic devices.


Author(s):  
Jiajun Song ◽  
Jianzhong Zheng ◽  
Anneng Yang ◽  
Hong Liu ◽  
Zeyu Zhao ◽  
...  

Two-dimensional (2D) conductive metal-organic frameworks (MOFs) can not only inherit the high porosity and tailorability of traditional MOFs but also exhibit unique charge transport properties, offering promising opportunities for applications...


2016 ◽  
Vol 85 (6) ◽  
pp. 064703 ◽  
Author(s):  
Shiori Sugiura ◽  
Kazuo Shimada ◽  
Naoya Tajima ◽  
Yutaka Nishio ◽  
Taichi Terashima ◽  
...  

1996 ◽  
pp. 449-452 ◽  
Author(s):  
G. Brunthaler ◽  
G. Bauer ◽  
G. Braithwaite ◽  
N. L. Mattey ◽  
P. Phillips ◽  
...  

2020 ◽  
Vol 6 (22) ◽  
pp. eaba6714 ◽  
Author(s):  
Shiqiang Zhao ◽  
Qingqing Wu ◽  
Jiuchan Pi ◽  
Junyang Liu ◽  
Jueting Zheng ◽  
...  

Two-dimensional van der Waals heterojunctions (2D-vdWHs) stacked from atomically thick 2D materials are predicted to be a diverse class of electronic materials with unique electronic properties. These properties can be further tuned by sandwiching monolayers of planar organic molecules between 2D materials to form molecular 2D-vdWHs (M-2D-vdWHs), in which electricity flows in a cross-plane way from one 2D layer to the other via a single molecular layer. Using a newly developed cross-plane break junction technique, combined with density functional theory calculations, we show that M-2D-vdWHs can be created and that cross-plane charge transport can be tuned by incorporating guest molecules. The M-2D-vdWHs exhibit distinct cross-plane charge transport signatures, which differ from those of molecules undergoing in-plane charge transport.


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