Effect of PbSO4-Oleate Coverage on Cesium Lead Halide Perovskite Quantum Dots to Control Halide Exchange Kinetics

The selective control of halide ion exchange in metal halide perovskite quantum dots (PQDs) plays an important role in determining their band gap and composition. In this study, CsPbX3 (X = Cl−, Br−, and I−) PQDs were self-assembled with PbSO4-oleate to form a peapod-like morphology to selectively control halide ion exchange. Considering the distinct absorption and bright luminescence characteristics of these PQDs, in situ UV-Vis. absorption and fluorescence spectroscopies were employed to monitor the time-dependent band gap and compositional changes of the PQDs. We determined that the halide exchange in the capped PQDs is hindered—unlike the rapid anion exchange in noncapped PQDs—by a reduction in the halide exchange kinetic rate depending on the extent of coverage of the PQDs. Thus, we tracked the halide ion exchange kinetics between CsPbBr3 and CsPbI3 PQDs, depending on the coverage, using in situ UV-Vis. absorption/photoluminescence spectroscopy. We regulated the halide exchange reaction rate by varying the capping reaction temperature of the PQDs. The capping hindered the halide exchange kinetics and increased the activation energy. These results will enable the development of white LEDs, photovoltaic cells, and photocatalysts with alternative structural designs based on the divalent composition of CsPbX3 PQDs.

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A novel in-situ process for high performance blue CsPbBr3 perovskite quantum dots via Cs ion-exchange in Sodium Titanium Silicate

Journal of Luminescence ◽

10.1016/j.jlumin.2020.117867 ◽

2021 ◽

Vol 232 ◽

pp. 117867

Author(s):

Ming Wang ◽

Songsheng Zheng ◽

Chufeng Chai ◽

Ziqi Fei ◽

Leiming Zheng ◽

...

Keyword(s):

Quantum Dots ◽

Ion Exchange ◽

High Performance ◽

Titanium Silicate ◽

Perovskite Quantum Dots

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Encapsulated Passivation of Perovskite Quantum Dot (CsPbBr3) Using a Hot-Melt Adhesive (EVA-TPR) for Enhanced Optical Stability and Efficiency

Crystals ◽

10.3390/cryst11040419 ◽

2021 ◽

Vol 11 (4) ◽

pp. 419

Author(s):

Saradh Prasad ◽

Mamduh J. Aljaafreh ◽

Mohamad S. AlSalhi ◽

Abeer Alshammari

Keyword(s):

Quantum Dots ◽

Band Gap ◽

Surface Defects ◽

Optoelectronic Devices ◽

Ethylene Vinyl Acetate ◽

Light Emitting ◽

Optical Stability ◽

Perovskite Quantum Dots ◽

Polymer Light Emitting Diodes ◽

Hot Melt

The notable photophysical characteristics of perovskite quantum dots (PQDs) (CsPbBr3) are suitable for optoelectronic devices. However, the performance of PQDs is unstable because of their surface defects. One way to address the instability is to passivate PQDs using different organic (polymers, oligomers, and dendrimers) or inorganic (ZnS, PbS) materials. In this study, we performed steady-state spectroscopic investigations to measure the photoluminescence (PL), absorption (A), transmission (T), and reflectance (R) of perovskite quantum dots (CsPbBr3) and ethylene vinyl acetate/terpene phenol (1%) (EVA-TPR (1%), or EVA) copolymer/perovskite composites in thin films with a thickness of 352 ± 5 nm. EVA is highly transparent because of its large band gap; furthermore, it is inexpensive and easy to process. However, the compatibility between PQDs and EVA should be established; therefore, a series of analyses was performed to compute parameters, such as the band gap, the coefficients of absorbance and extinction, the index of refractivity, and the dielectric constant (real and imaginary parts), from the data obtained from the above investigation. Finally, the optical conductivities of the films were studied. All these analyses showed that the EVA/PQDs were more efficient and stable both physically and optically. Hence, EVA/PQDs could become copolymer/perovskite active materials suitable for optoelectronic devices, such as solar cells and perovskite/polymer light-emitting diodes (PPLEDs).

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Lead-Free, Blue Emitting Bismuth Halide Perovskite Quantum Dots

Angewandte Chemie International Edition ◽

10.1002/anie.201608160 ◽

2016 ◽

Vol 55 (48) ◽

pp. 15012-15016 ◽

Cited By ~ 246

Author(s):

Meiying Leng ◽

Zhengwu Chen ◽

Ying Yang ◽

Zha Li ◽

Kai Zeng ◽

...

Keyword(s):

Quantum Dots ◽

Lead Free ◽

Perovskite Quantum Dots ◽

Halide Perovskite

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Ultra-Halide-Rich Synthesis of Stable Pure Tin-Based Halide Perovskite Quantum Dots: Implications for Photovoltaics

ACS Applied Nano Materials ◽

10.1021/acsanm.1c00324 ◽

2021 ◽

Author(s):

Feng Liu ◽

Junke Jiang ◽

Taro Toyoda ◽

Muhammad Akmal Kamarudin ◽

Shuzi Hayase ◽

...

Keyword(s):

Quantum Dots ◽

Perovskite Quantum Dots ◽

Halide Perovskite

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Burstein-Moss shift of lead halide perovskite quantum dots induced by electron injection from graphene oxide

Applied Surface Science ◽

10.1016/j.apsusc.2021.149003 ◽

2021 ◽

Vol 545 ◽

pp. 149003

Author(s):

Shengnan Ni ◽

Haijun Qin ◽

Jianfeng Wen ◽

Xinyu Li ◽

Ming Li ◽

...

Keyword(s):

Quantum Dots ◽

Graphene Oxide ◽

Electron Injection ◽

Perovskite Quantum Dots ◽

Halide Perovskite ◽

Lead Halide

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Heterogeneous Post-Passivation of Inorganic Cesium Lead Halide Perovskite Quantum Dots for Efficient Electroluminescent Devices

Journal of Materials Chemistry C ◽

10.1039/d0tc05856d ◽

2021 ◽

Author(s):

Xuefei Li ◽

Qingqing Yang ◽

Liuqing Yang ◽

Shumeng Wang ◽

Junqiao Ding ◽

...

Keyword(s):

Quantum Dots ◽

Electroluminescent Devices ◽

Perovskite Quantum Dots ◽

Halide Perovskite ◽

Lead Halide

A heterogeneous post-passivation has been demonstrated by using formamidiniu bromide (FABr) to compensate the surface bromo vacancy of inorganic cesium lead halide perovskite quantum dots (QDs). Benefitting from its limited...

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