Investigation of the Role of the Environment on the Photoluminescence and the Exciton Relaxation of CsPbBr3 Nanocrystals Thin Films

Marco Anni; Arianna Cretì; Yuhai Zhang; Maria Luisa De Giorgi; Mauro Lomascolo

doi:10.3390/app10062148

Investigation of the Role of the Environment on the Photoluminescence and the Exciton Relaxation of CsPbBr3 Nanocrystals Thin Films

Applied Sciences ◽

10.3390/app10062148 ◽

2020 ◽

Vol 10 (6) ◽

pp. 2148 ◽

Cited By ~ 1

Author(s):

Marco Anni ◽

Arianna Cretì ◽

Yuhai Zhang ◽

Maria Luisa De Giorgi ◽

Mauro Lomascolo

Keyword(s):

Thin Films ◽

Gas Sensors ◽

Free Exciton ◽

Intensity Increase ◽

Optical Investigation ◽

Relaxation Dynamics ◽

Dynamic Effects ◽

Radiative Relaxation ◽

Pl Intensity

In this work, we present a detailed optical investigation of the effects of the environment on the photoluminescence (PL) spectra and the relaxation dynamics of pristine and aged CsPbBr3 nanocrystal (NC) thin films. We demonstrate that, contrary to previous results on similar NCs, the PL intensity of pristine NCs is higher when the sample is in wet air than in vacuum, due to the passivation of defects reducing the free exciton trapping and the bound excitons non-radiative relaxation. The aged NCs show a PL intensity increase in wet air nine times stronger than the pristine ones, due to an interplay between static and dynamic effects, increasing the number of emitting NCs and reducing the non-radiative recombination rate of free excitons. These results improve the understanding of the possible interactions between perovskite NCs and the environment, which could be relevant for the development of optical gas sensors exploiting perovskite NCs.

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Polarization switching and relaxation dynamics of bismuth layered ferroelectric thin films: Role of oxygen defect sites and crystallinity

Physical Review B ◽

10.1103/physrevb.84.094112 ◽

2011 ◽

Vol 84 (9) ◽

Cited By ~ 15

Author(s):

Ji Hye Lee ◽

Ran Hee Shin ◽

William Jo

Keyword(s):

Thin Films ◽

Polarization Switching ◽

Ferroelectric Thin Films ◽

Oxygen Defect ◽

Relaxation Dynamics ◽

Defect Sites

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Role of Pt Aggregates in Pt/SnO[sub 2] Thin Films Used as Gas Sensors Investigations of the Catalytic Effect

Journal of The Electrochemical Society ◽

10.1149/1.1393870 ◽

2000 ◽

Vol 147 (8) ◽

pp. 3131 ◽

Cited By ~ 27

Author(s):

M. Gaidi ◽

J. L. Hazemann ◽

I. Matko ◽

B. Chenevier ◽

M. Rumyantseva ◽

...

Keyword(s):

Thin Films ◽

Gas Sensors ◽

Catalytic Effect

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Origins of Light Emission and Efficiency Saturation of the Photoluminescence of GaN Nanocrystallites

MRS Proceedings ◽

10.1557/proc-798-y5.73 ◽

2003 ◽

Vol 798 ◽

Author(s):

Xiang-Bai Chen ◽

John L. Morrison ◽

Margaret K. Penner ◽

Jennifer Elle ◽

Leah Bergman ◽

...

Keyword(s):

Thin Films ◽

Emission Line ◽

Laser Heating ◽

Laser Power ◽

Room Temperature ◽

Light Emission ◽

Free Exciton ◽

Strong Emission ◽

Intensity Saturation ◽

Pl Intensity

ABSTRACTThe photoluminescence (PL) properties of GaN nanorods were studied utilizing UV micro-photoluminescence. The room temperature PL of the GaN nanorods exhibits one strong emission line. The PL intensity as a function of the laser power was investigated in order to determine whether this emission originates from an excitonic or a bandgap recombination process. Our analysis indicates that the PL of the rods is excitonic-like and very similar to the behavior of the free exciton A in GaN thin films. However, for a relatively large and compact ensemble of rods, the PL intensity exhibits a significant saturation occurring already at relatively low laser power. We attribute the intensity saturation to the laser heating and heat trapping which takes place in the enclosure of the ensemble.

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The study of interfacial reactions of nickel thin films on GaAs

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100074616 ◽

1983 ◽

Vol 41 ◽

pp. 156-157

Author(s):

L.J. Chen ◽

Y.F. Hsieh

Keyword(s):

Thin Films ◽

Integrated Circuits ◽

Interfacial Reactions ◽

Metal Contacts ◽

Nickel Thin Films ◽

Thin Foils ◽

The Status ◽

Si Doped ◽

Electron Microscopes

One measure of the maturity of a device technology is the ease and reliability of applying contact metallurgy. Compared to metal contact of silicon, the status of GaAs metallization is still at its primitive stage. With the advent of GaAs MESFET and integrated circuits, very stringent requirements were placed on their metal contacts. During the past few years, extensive researches have been conducted in the area of Au-Ge-Ni in order to lower contact resistances and improve uniformity. In this paper, we report the results of TEM study of interfacial reactions between Ni and GaAs as part of the attempt to understand the role of nickel in Au-Ge-Ni contact of GaAs.N-type, Si-doped, (001) oriented GaAs wafers, 15 mil in thickness, were grown by gradient-freeze method. Nickel thin films, 300Å in thickness, were e-gun deposited on GaAs wafers. The samples were then annealed in dry N2 in a 3-zone diffusion furnace at temperatures 200°C - 600°C for 5-180 minutes. Thin foils for TEM examinations were prepared by chemical polishing from the GaA.s side. TEM investigations were performed with JE0L- 100B and JE0L-200CX electron microscopes.

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Transmission Electron Microscopy studies of texture of Cr underlayer of magnetic recording hard disk

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087215 ◽

1991 ◽

Vol 49 ◽

pp. 580-581

Author(s):

L. Tang ◽

G. Thomas ◽

M. R. Khan ◽

S. L. Duan

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

Magnetic Recording ◽

Magnetic Thin Films ◽

Magnetic Films ◽

Substrate Bias ◽

Epitaxial Relationship ◽

Transmission Electron

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.

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Transmission Electron Microscopy of Evaporated Perylene Thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100135289 ◽

1990 ◽

Vol 48 (2) ◽

pp. 336-337

Author(s):

C. Ewins ◽

J.R. Fryer

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

Molecular Electronics ◽

High Vacuum ◽

Amorphous Layer ◽

Electric Heater ◽

Transmission Electron ◽

Polycyclic Aromatic

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.

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Degradation in a Methyl-phenyl Co-Polymeric Polysilane for LED Applications

MRS Proceedings ◽

10.1557/proc-769-h4.3 ◽

2003 ◽

Vol 769 ◽

Cited By ~ 2

Author(s):

Asha Sharma ◽

Deepak ◽

Monica Katiyar ◽

Satyendra Kumar ◽

V. Chandrasekhar ◽

...

Keyword(s):

Thin Films ◽

Molecular Weight ◽

Light Source ◽

Room Temperature ◽

Light Exposure ◽

Room Temperature Photoluminescence ◽

Pl Spectrum ◽

Pl Intensity ◽

Methyl Phenyl

AbstractThe optical degradation of polysilane copolymer has been studied in spin cast thin films and solutions using light source of 325 nm wavelength. The room temperature photoluminescence (PL) spectrum of these films show a sharp emission at 368 nm when excited with a source of 325 nm. However, the PL intensity deteriorates with time upon light exposure. Further the causes of this degradation have been examined by characterizing the material for its transmission behaviour and changes occurring in molecular weight as analysed by GPC data.

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On the Use of MOFs and ALD Layers as Nanomembranes for the Enhancement of Gas Sensors Selectivity

Nanomaterials ◽

10.3390/nano9111552 ◽

2019 ◽

Vol 9 (11) ◽

pp. 1552 ◽

Cited By ~ 3

Author(s):

Weber ◽

Graniel ◽

Balme ◽

Miele ◽

Bechelany

Keyword(s):

Thin Films ◽

Gas Sensors ◽

Gas Sensing ◽

Metal Organic Frameworks ◽

Atomic Layer ◽

Operational Performance ◽

Layer Deposition ◽

Metal Organic ◽

Further Development ◽

Different Gases

Improving the selectivity of gas sensors is crucial for their further development. One effective route to enhance this key property of sensors is the use of selective nanomembrane materials. This work aims to present how metal-organic frameworks (MOFs) and thin films prepared by atomic layer deposition (ALD) can be applied as nanomembranes to separate different gases, and hence improve the selectivity of gas sensing devices. First, the fundamentals of the mechanisms and configuration of gas sensors will be given. A selected list of studies will then be presented to illustrate how MOFs and ALD materials can be implemented as nanomembranes and how they can be implemented to improve the operational performance of gas sensing devices. This review comprehensively shows the benefits of these novel selective nanomaterials and opens prospects for the sensing community.

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