Lead-free low-dimensional tin halide perovskites with functional organic spacers: breaking the charge-transport bottleneck

2019 ◽  
Vol 7 (28) ◽  
pp. 16742-16747 ◽  
Author(s):  
Ming-Gang Ju ◽  
Jun Dai ◽  
Liang Ma ◽  
Yuanyuan Zhou ◽  
Wanzhen Liang ◽  
...  
Keyword(s):  
Charge Transport ◽  
Electronic Structures ◽  
Band Alignment ◽  
Lead Free ◽  
Type Ii ◽  
Organic Species ◽  
New Family ◽  
Halide Perovskites ◽  
Low Dimensional

A new family of 2D OIHPs that may potentially break the charge-transport ‘bottleneck’ are designed by introducing π-conjugation organic species as the spacers. Their electronic structures are predicted to exhibit type-II band alignment.

Lead-Free Metal Halide Perovskite Nanocrystals for Photocatalysis in Water

2019 ◽  
Author(s):  
Subhajit Bhattacharjee ◽  
Sonu Pratap Chaudhary ◽  
Sayan Bhattacharyya
Keyword(s):  
Charge Carrier ◽  
Wide Spectrum ◽  
Real Life ◽  
Metal Halide ◽  
Lead Free ◽  
Water Medium ◽  
Type I ◽  
Type Ii ◽  
Perovskite Layer ◽  
Halide Perovskites

<p>Metal halide perovskites with high absorption coefficient, direct generation of free charge carriers, excellent ambipolar charge carrier transport properties, point-defect tolerance, compositional versatility and solution processability are potentially transforming the photovoltaics and optoelectronics industries. However their limited ambient stability, particularly those of iodide perovskites, obscures their use as photocatalysts especially in aqueous medium. In an unprecedented approach we have exploited the photo-absorption property of the less toxic lead-free Cs<sub>3</sub>Bi<sub>2</sub>X<sub>9 </sub>(X = Br, I) nanocrystals (NCs) to catalyse the degradation of water pollutant organic dye, methylene blue (MB) in presence of visible light at room temperature. After providing a proof-of-concept with bromide perovskites in isopropanol, the perovskites are employed as photocatalysts in water medium by designing perovskite/Ag<sub>2</sub>S and perovskite/TiO<sub>2 </sub>composite systems, with Type I (or quasi Type II) and Type II alignments, respectively. Ag<sub>2</sub>S and TiO<sub>2</sub> coatings decelerate penetration of water into the perovskite layer while facilitating charge carrier extraction. With a minimal NC loading, Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub>/Ag<sub>2</sub>S degrades ~90% MB within an hour. Our approach has the potential to unravel the photocatalytic properties of metal halide perovskites for a wide spectrum of real-life applications. </p>

scholarly journals Enhanced Luminescence and Mechanistic Studies on Mn-doped Double Layered Perovskite Phosphors: Cs4Mn1−xCdxBi2Cl12

2020 ◽  
Author(s):  
Brenda Vargas ◽  
Diana T. Reyes-Castillo ◽  
Eduardo Coutino-Gonzalez ◽  
Citlali Sánchez-Aké ◽  
Carlos Ramos ◽  
...  
Keyword(s):  
Magnetic Coupling ◽  
Layered Perovskite ◽  
Great Promise ◽  
New Family ◽  
Halide Perovskites ◽  
Optoelectronic Applications ◽  
The Stability ◽  
Low Dimensional ◽  
Stability Issues ◽  
Mn Doped

Halide perovskites offer great promise for optoelectronic applications, but stability issues continue to hinder its implementation and long-term stability. The stability of all-inorganic halide perovskites and the inherent quantum confinement of low dimensional perovskites can be harnessed to synthesize materials with high PL efficiency. An example of such materials is the recently reported new family of layered double perovskites, Cs4Mn1−xCdxBi2Cl12. Herein, we report a new synthetic procedure that enhances the maximum PLQY of this family materials to up 79.5%, a 20% enhancement from previous reports and the highest reported for a Mn-doped halide perovskite. Importantly, stability tests demonstrate that these materials are very stable towards humidity, UV irradiation, and temperature. Finally, we investigated the photophysics, the effects of magnetic coupling and temperature in the PL efficiency and proposed a mechanism for the emission process. Our results highlight the potential of this family of materials and related layered all-inorganic perovskites for solid-state lighting and optoelectronic applications<p></p>

scholarly journals Enhanced Luminescence and Mechanistic Studies on Mn-doped Double Layered Perovskite Phosphors: Cs4Mn1−xCdxBi2Cl12

2020 ◽  
Author(s):  
Brenda Vargas ◽  
Diana T. Reyes-Castillo ◽  
Eduardo Coutino-Gonzalez ◽  
Citlali Sánchez-Aké ◽  
Carlos Ramos ◽  
...  
Keyword(s):  
Magnetic Coupling ◽  
Layered Perovskite ◽  
Great Promise ◽  
New Family ◽  
Halide Perovskites ◽  
Optoelectronic Applications ◽  
The Stability ◽  
Low Dimensional ◽  
Stability Issues ◽  
Mn Doped

Halide perovskites offer great promise for optoelectronic applications, but stability issues continue to hinder its implementation and long-term stability. The stability of all-inorganic halide perovskites and the inherent quantum confinement of low dimensional perovskites can be harnessed to synthesize materials with high PL efficiency. An example of such materials is the recently reported new family of layered double perovskites, Cs4Mn1−xCdxBi2Cl12. Herein, we report a new synthetic procedure that enhances the maximum PLQY of this family materials to up 79.5%, a 20% enhancement from previous reports and the highest reported for a Mn-doped halide perovskite. Importantly, stability tests demonstrate that these materials are very stable towards humidity, UV irradiation, and temperature. Finally, we investigated the photophysics, the effects of magnetic coupling and temperature in the PL efficiency and proposed a mechanism for the emission process. Our results highlight the potential of this family of materials and related layered all-inorganic perovskites for solid-state lighting and optoelectronic applications<p></p>

Lead-Free Metal Halide Perovskite Nanocrystals for Photocatalysis in Water

2019 ◽  
Author(s):  
Subhajit Bhattacharjee ◽  
Sonu Pratap Chaudhary ◽  
Sayan Bhattacharyya
Keyword(s):  
Charge Carrier ◽  
Wide Spectrum ◽  
Real Life ◽  
Metal Halide ◽  
Lead Free ◽  
Water Medium ◽  
Type I ◽  
Type Ii ◽  
Perovskite Layer ◽  
Halide Perovskites

<p>Metal halide perovskites with high absorption coefficient, direct generation of free charge carriers, excellent ambipolar charge carrier transport properties, point-defect tolerance, compositional versatility and solution processability are potentially transforming the photovoltaics and optoelectronics industries. However their limited ambient stability, particularly those of iodide perovskites, obscures their use as photocatalysts especially in aqueous medium. In an unprecedented approach we have exploited the photo-absorption property of the less toxic lead-free Cs<sub>3</sub>Bi<sub>2</sub>X<sub>9 </sub>(X = Br, I) nanocrystals (NCs) to catalyse the degradation of water pollutant organic dye, methylene blue (MB) in presence of visible light at room temperature. After providing a proof-of-concept with bromide perovskites in isopropanol, the perovskites are employed as photocatalysts in water medium by designing perovskite/Ag<sub>2</sub>S and perovskite/TiO<sub>2 </sub>composite systems, with Type I (or quasi Type II) and Type II alignments, respectively. Ag<sub>2</sub>S and TiO<sub>2</sub> coatings decelerate penetration of water into the perovskite layer while facilitating charge carrier extraction. With a minimal NC loading, Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub>/Ag<sub>2</sub>S degrades ~90% MB within an hour. Our approach has the potential to unravel the photocatalytic properties of metal halide perovskites for a wide spectrum of real-life applications. </p>

scholarly journals Formation of Corrugated 2D Tin Iodide Perovskites and Their Use as Lead-Free Solar Absorbers

2020 ◽  
Author(s):  
Benny Febriansyah ◽  
Yulia Lekina ◽  
Jagjit Kaur ◽  
Thomas J. N. Hooper ◽  
Padinhare Cholakkal Harikesh ◽  
...  
Keyword(s):  
Metal Halide ◽  
Lead Free ◽  
Supramolecular Interactions ◽  
Lead Iodide ◽  
Group 14 ◽  
Halide Perovskites ◽  
Tin Iodide ◽  
Low Dimensional ◽  
Light Absorbers ◽  
The Impact

Major strides have been made in the development of materials and devices based around low-dimensional hybrid group 14 metal halide perovskites. Thus far, this work has mostly focused upon compounds containing highly toxic Pb, with the analogous less toxic Sn materials being comparatively poorly evolved. In response, the study herein aims to (i) provide insight into the impact of templating cation upon the structure of 2D tin iodide perovskites, and (ii) examine their potential as light absorbers for photovoltaic (PV) cells. It was discovered through systematic tuning of organic dications, that imidazolium rings are able to induce formation of (110)-oriented materials, including the first examples of “3 × 3” corrugated Sn-I perovskites. This structural outcome is a consequence of a combination of supramolecular interactions of the two endocyclic N-atoms in the imidazolium functionalities with the Sn-I framework and the higher tendency of Sn<sup>2+</sup> ions to stereochemically express their 5s<sup>2</sup> lone pairs relative to the 6s<sup>2</sup> electrons of Pb<sup>2+</sup>. More importantly, the resulting materials feature very short separations between their 2D inorganic layers with iodide–iodide (I···I) contacts as small as 4.174 Å, which is amongst the shortest ever recorded for 2D tin iodide perovskites. The proximate inorganic distances, combined with the polarizable nature of the imidazolium moiety, eases the separation of photogenerated charge within the materials. This is evident from the excitonic activation energies as low as 83(10) meV, measured for ImEA[SnI<sub>4</sub>]. When combined with superior light absorption capabilities relative to their lead congeners, this allowed fabrication of lead-free solar cells with incident photon-to-current and power conversion efficiencies of up to 70 % and 2.26 %, respectively, which are amongst the highest values reported for pure 2D group 14 metal halide perovskites. In fact, these values are superior to the corresponding lead iodide material, which demonstrates that 2D Sn-based materials have significant potential as less toxic alternatives to their Pb counterparts.

Electronic structures of in-plane two-dimensional transition-metal dichalcogenide heterostructures

2015 ◽  
Vol 17 (43) ◽  
pp. 29380-29386 ◽  
Author(s):  
Wei Wei ◽  
Ying Dai ◽  
Qilong Sun ◽  
Na Yin ◽  
Shenghao Han ◽  
...  
Keyword(s):  
Transition Metal ◽  
Electronic Structures ◽  
Band Alignment ◽  
Transition Metal Dichalcogenide ◽  
Type Ii ◽  
Two Dimensional ◽  
Band Bending

In-plane two-dimensional MoS2/WS2 and MoSe2/WS2 heterostructures have been identified to show type-II band alignment and interface band bending.

Recent Advances toward Environment-Friendly Photodetectors Based on Lead-Free Metal Halide Perovskites and Perovskite Derivatives

2021 ◽  
Author(s):  
Ying Li ◽  
Zhifeng Shi ◽  
Wenqing Liang ◽  
Jingli Ma ◽  
Xu Chen ◽  
...  
Keyword(s):  
Charge Transport ◽  
Carrier Mobility ◽  
Optoelectronic Properties ◽  
Metal Halide ◽  
Lead Free ◽  
Environment Friendly ◽  
High Carrier Mobility ◽  
High Carrier ◽  
Halide Perovskites ◽  
Free Metal

Recently, metal-halide perovskites have emerged as promising materials for photodetectors (PDs) applications owing to their superior optoelectronic properties, such as ambipolar charge transport characteristics, high carrier mobility, and so on....

scholarly journals Formation of Corrugated 2D Tin Iodide Perovskites and Their Use as Lead-Free Solar Absorbers

2020 ◽  
Author(s):  
Benny Febriansyah ◽  
Yulia Lekina ◽  
Jagjit Kaur ◽  
Thomas J. N. Hooper ◽  
Padinhare Cholakkal Harikesh ◽  
...  
Keyword(s):  
Metal Halide ◽  
Lead Free ◽  
Supramolecular Interactions ◽  
Lead Iodide ◽  
Group 14 ◽  
Halide Perovskites ◽  
Tin Iodide ◽  
Low Dimensional ◽  
Light Absorbers ◽  
The Impact

Major strides have been made in the development of materials and devices based around low-dimensional hybrid group 14 metal halide perovskites. Thus far, this work has mostly focused upon compounds containing highly toxic Pb, with the analogous less toxic Sn materials being comparatively poorly evolved. In response, the study herein aims to (i) provide insight into the impact of templating cation upon the structure of 2D tin iodide perovskites, and (ii) examine their potential as light absorbers for photovoltaic (PV) cells. It was discovered through systematic tuning of organic dications, that imidazolium rings are able to induce formation of (110)-oriented materials, including the first examples of “3 × 3” corrugated Sn-I perovskites. This structural outcome is a consequence of a combination of supramolecular interactions of the two endocyclic N-atoms in the imidazolium functionalities with the Sn-I framework and the higher tendency of Sn<sup>2+</sup> ions to stereochemically express their 5s<sup>2</sup> lone pairs relative to the 6s<sup>2</sup> electrons of Pb<sup>2+</sup>. More importantly, the resulting materials feature very short separations between their 2D inorganic layers with iodide–iodide (I···I) contacts as small as 4.174 Å, which is amongst the shortest ever recorded for 2D tin iodide perovskites. The proximate inorganic distances, combined with the polarizable nature of the imidazolium moiety, eases the separation of photogenerated charge within the materials. This is evident from the excitonic activation energies as low as 83(10) meV, measured for ImEA[SnI<sub>4</sub>]. When combined with superior light absorption capabilities relative to their lead congeners, this allowed fabrication of lead-free solar cells with incident photon-to-current and power conversion efficiencies of up to 70 % and 2.26 %, respectively, which are amongst the highest values reported for pure 2D group 14 metal halide perovskites. In fact, these values are superior to the corresponding lead iodide material, which demonstrates that 2D Sn-based materials have significant potential as less toxic alternatives to their Pb counterparts.

Meso-Scale Modelling of Charge Transport in Halide Perovskites

2018 ◽  
Author(s):  
Matthew Wolf ◽  
Lewis Irvine ◽  
Ian Thompson ◽  
Alison Walker
Keyword(s):  
Charge Transport ◽  
Scale Modelling ◽  
Halide Perovskites ◽  
Meso Scale

A first-principles study on the electronic and optical properties of a type-II C2N/g-ZnO van der Waals heterostructure

2021 ◽  
Vol 23 (6) ◽  
pp. 3963-3973
Author(s):  
Jianxun Song ◽  
Hua Zheng ◽  
Minxia Liu ◽  
Geng Zhang ◽  
Dongxiong Ling ◽  
...  
Keyword(s):  
Optical Properties ◽  
Dft Calculations ◽  
First Principles ◽  
Van Der Waals ◽  
Band Alignment ◽  
Type Ii ◽  
Electronic And Optical Properties ◽  
Direct Bandgap ◽  
Van Der Waals Heterostructure ◽  
Vdw Heterostructure

The structural, electronic and optical properties of a new vdW heterostructure, C2N/g-ZnO, with an intrinsic type-II band alignment and a direct bandgap of 0.89 eV at the Γ point are extensively studied by DFT calculations.

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