Effect of organic cation states on electronic properties of mixed organic–inorganic halide perovskite clusters

2019 ◽  
Vol 21 (15) ◽  
pp. 8161-8169 ◽  
Author(s):  
Sergei Manzhos ◽  
Amrita Pal ◽  
Yingqian Chen ◽  
Giacomo Giorgi

We study the effect of organic cation-centered states in mixed organic–inorganic halide perovskite clusters on the bandstructure and optical properties.

CrystEngComm ◽  
2021 ◽  
Author(s):  
Maryam Bari ◽  
Hua Wu ◽  
Alexei A. Bokov ◽  
Rana Faryad Ali ◽  
Hamel N. Tailor ◽  
...  

Growth of MAPbX3 (X = I, Br, and Cl) single crystals by room temperature crystallization (RTC) method, and the crystallization pathway illustrated by the solubility curve of MAPbCl3 in DMSO, compared with inverse temperature crystallization (ITC) method.


Author(s):  
Li Liu ◽  
Chuan-Lu Yang ◽  
Zhaopeng Sun ◽  
Meishan Wang ◽  
Xiano-Guang Ma

The direct laser cooling is a very promising method to obtain cold molecules for various applications. However, a molecule with satisfactory electronic and optical properties for the optical scheme is...


2017 ◽  
Vol 5 (1) ◽  
pp. 149-158 ◽  
Author(s):  
Bartłomiej Cichy ◽  
Dominika Wawrzynczyk ◽  
Marek Samoc ◽  
Wiesław Stręk

Electronic as well as third-order nonlinear optical properties of chalcopyrite AgInS2 and non-stoichiometric spinel AgIn5S8 quantum dots compared with corresponding Zn2+ alloyed compounds are presented in this work.


Author(s):  
Yan Liu ◽  
Qiang Zhou ◽  
Yalan Yan ◽  
Liang Li ◽  
Jian Zhu ◽  
...  

Pressure has been considered as an effective technique to modulate the structural, electronic, and optical properties of transition metal dichalcogenides (TMDs) materials. Here, by performing in situ high pressure Raman,...


Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 876 ◽  
Author(s):  
Qi Qian ◽  
Lei Peng ◽  
Yu Cui ◽  
Liping Sun ◽  
Jinyan Du ◽  
...  

We systematically study, by using first-principles calculations, stabilities, electronic properties, and optical properties of GexSn1-xSe alloy made of SnSe and GeSe monolayers with different Ge concentrations x = 0.0, 0.25, 0.5, 0.75, and 1.0. Our results show that the critical solubility temperature of the alloy is around 580 K. With the increase of Ge concentration, band gap of the alloy increases nonlinearly and ranges from 0.92 to 1.13 eV at the PBE level and 1.39 to 1.59 eV at the HSE06 level. When the Ge concentration x is more than 0.5, the alloy changes into a direct bandgap semiconductor; the band gap ranges from 1.06 to 1.13 eV at the PBE level and 1.50 to 1.59 eV at the HSE06 level, which falls within the range of the optimum band gap for solar cells. Further optical calculations verify that, through alloying, the optical properties can be improved by subtle controlling the compositions. Since GexSn1-xSe alloys with different compositions have been successfully fabricated in experiments, we hope these insights will contribute to the future application in optoelectronics.


Author(s):  
Pooja Basera ◽  
Arunima Singh ◽  
Deepika Gill ◽  
Saswata Bhattacharya

Lead iodide perovskites have attracted considerable interest as promising energy-materials. However, till date, several key electronic properties such as optical properties, effective mass, exciton binding energy and the radiative exciton...


2021 ◽  
Author(s):  
C. Meric Guvenc ◽  
sinan balci

<p><b>Two-dimensional lead halide perovskite nanoplatelets (2D LHP NPLs) have been emerging as one of the most promising semiconductor nanomaterials due to their narrow absorption and emission line widths, tunable bandgaps, high exciton binding energies, high defect tolerance as well as highly localized energy states. Colloidal synthesis of 2D LHP NPLs is generally performed using hot-injection or ligand assisted precipitation techniques (LARP). In the LARP method, perovskites are synthesized in polar solvents, which decrease the stability of the 2D LHP NPLs due to their weakly bonded nature. In fact, the presence of residual polar solvent in the LHP NPL colloid can cause deterioration of thickness uniformity, degradation of NPLs to parent precursors, and undesired phase transformations. Herein, for the first time, we report facile seed-mediated synthesis route of monolayer, 2-monolayers, and thicker lead halide perovskite nanoplatelets without using A site cation halide salt (AX</b><b>;</b><b> A = Cesium, methylammonium, formamidinium and, X = Cl, Br, I) and long chain alkylammonium halide salts (LX; L = oleylammonium, octylammonium, butylammonium and, X = Cl, Br, I). The seed solution has been synthesized by reacting lead (II) halide salt and coordinating ligands (oleylamine or octylamine and oleic acid) in nonpolar high boiling solvent (1-octadecene). The seed mediated synthesis has been carried out in hexane by reacting seed solution with A-site cation precursors (Cs-oleate, FA-oleate, or diluted MA solution in hexane) under ambient conditions. More importantly, the seed mediated growth of NPLs has been tracked for the first time by performing in-situ optical measurements. Furthermore, the optical properties and morphologies of the seeds have been extensively studied. We find that our facile synthesis route provides highly stable, monodisperse NPLs with narrow absorption, and photoluminescence line widths (68-201 meV), and high PLQY (37.6-1.66% for 2ML NPLs). Furthermore, anion exchange reactions have been performed by mixing pre-synthesized LHP NPLs with counter halide seeds. The optical properties of NPLs have been affectively tuned by postsynthetic chemical reactions without changing the thickness of the NPLs. We anticipate that our new synthetic route provides further understanding of growth dynamics of LHP NPLs.</b></p>


2021 ◽  
Author(s):  
Dahua Ren ◽  
Qiang Li ◽  
Kai Qian ◽  
Xingyi Tan

Abstract Vertically stacked heterostructures have received extensive attention because of their tunable electronic structures and outstanding optical properties. In this work, we have studied the structural, electronic and optical properties of vertically stacked GaS-SnS2 heterostructure under the frame of density functional theory. We find that the stacked GaS-SnS2 heterostructure is a semiconductor with suitable indirect band gaps of 1.82 eV, exhibiting a type-II band alignment for easily separating the photo-generated carriers. The electronic properties of GaS-SnS2 heterostructure can be effectively tuned by external strain and electric field. The optical absorption of GaS-SnS2 heterostructure is more enhanced by comparison with the GaS monolayer and SnS2 monolayer in the visible light. Our results suggest that GaS-SnS2 heterostructure is a promising candidate for the photocatalyst and photoelectronic devices in visible light.


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