Temperature dependent photoluminescence of composition tunable Zn_xAgInSe quantum dots and temperature sensor application

fabrication of blue-emitting Cd-free QDs are still under development. [7-10] Above all, the charging of QDs is an obstacle for manufacturing QD-LEDs with good performance. [11] The simple mechanism of EL is that electrons and holes are formed by charge injection, and light is generated by the electron-hole pair recombination. Hence, it is essential to understand the charging process by mimicking EL processes. The complementary combination of spectroscopic technology and electrochemical control helps emulate EL and explain the charging process whether the charges occupy quantum states or trap states. Recently, there has been an increase in research to improve QD luminescence capabilities and charge extraction properties by performing electrochemical charging studies on QD films. [1,12,13] Li et al. [13] have shown that electron injection into the ground excitonic state of CdSe/CdS QDs leads to the bleaching of 1S 3/2 1S e transition because of 1S e state filling. Qin et al. [14] have investigated how the photoluminescence (PL) lifetime changes in CdSeS/ZnS QD under electrochemical control with blinking dynamics. Gooding et al. [15] have studied the effects of hole and electron injection on the PL of CdSe/ CdS/ZnS QDs. Many studies have revealed the effect of electron injection on the optical properties in Cd-based QDs, which leads to environmental issues. Environmentally friendly III-V semiconductors, especially InP QDs, have recently emerged as the best alternative to toxic II-VI semiconductors. [16-17] Meanwhile, the surfaces of InP core QDs are easily oxidized when they are exposed to oxygen environments. As a countermeasure, overcoating nanocrystals with wider band-gap materials has proven to be the best option to increase stability against photo-oxidation and to enhance the photoluminescence quantum yield (PL QY). [5,18,19] For example, the inorganic core can be surrounded by the shell, such as ZnSe and ZnS. [20] Möbius et al. reported that the electrical charges generated by application of a mechanical load are injected into the QDs, leading to PL quenching in InP/ZnS-based device. [17] However, the spectroelectrochemical properties were not yet reported in InP QDs to the best of our knowledge. Recently, we have reported highly luminescent InP/ZnSe/ZnS QDs synthesized with as much high efficiency as state-of-the-art Cd-based QDs. [21] In this study, we analyze the spectroelectrochemical properties depending on mid-shell thickness to identify the effect of charging on highly luminescent InP Semiconductor quantum dots (QDs) are spotlighted as a key type of emissive material for the next generation of light-emitting diodes (LEDs). This work presents the investigation of the electrochemical charging effect on the absorption and emission of the InP/ZnSe/ZnS QDs with different mid-shell thicknesses. The excitonic peak is gradually bleached during electrochemical charging, which is caused by 1S e (or 1S h) state filling when the electron (or hole) is injected into the InP core. Additional charges also lead to photo...

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“…The temperature‐dependent PL intensity can be fitted by the following Arrhenius formula (Equation ()). [ 41–44 ]

\begin{matrix} I (T) = \frac{I (0)}{1 + A \times \exp (\frac{- E_{a}}{k_{B} T})} \end{matrix}

…”

Section: Resultsmentioning

confidence: 99%

Electrochemical Charging Effect on the Optical Properties of InP/ZnSe/ZnS Quantum Dots

Park

Won

Kim

et al. 2020

Small

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“…Current nanothermometry techniques include contact thermometry, including scanning thermal microscopy [20][21][22] and micro-thermocouple devices [23]. Non-contact thermometry techniques that elucidate temperature changes noninvasively are particularly attractive, including infrared thermography [24,25], quantum dot-based fluorescence thermography [26][27][28][29], and organic dye-based luminescence or fluorescence thermography [30][31][32][33]. Fluorescence thermography, in particular, offers high detection sensitivity and spatial resolution limited only by the diffraction limit on the order of a few hundred nanometers.…”

Section: Introductionmentioning

confidence: 99%

Surface Plasmon Enhanced Fluorescence Temperature Mapping of Aluminum Nanoparticle Heated by Laser

Zakiyyan

Darr

Chen

et al. 2021

Sensors

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Partially aggregated Rhodamine 6G (R6G) dye is used as a lights-on temperature sensor to analyze the spatiotemporal heating of aluminum nanoparticles (Al NPs) embedded within a tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride (THV) fluoropolymer matrix. The embedded Al NPs were photothermally heated using an IR laser, and the fluorescent intensity of the embedded dye was monitored in real time using an optical microscope. A plasmonic grating substrate enhanced the florescence intensity of the dye while increasing the optical resolution and heating rate of Al NPs. The fluorescence intensity was converted to temperature maps via controlled calibration. The experimental temperature profiles were used to determine the Al NP heat generation rate. Partially aggregated R6G dyes, combined with the optical benefits of a plasmonic grating, offered robust temperature sensing with sub-micron spatial resolution and temperature resolution on the order of 0.2 °C.

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“…20,21 The most popular way towards luminescent AISe and Zndoped AISe QDs is the incorporation of In 3+ into primary Ag 2 Se particles that can be achieved by relatively hightemperature hot-injection syntheses in coordinating solvents (such as trioctylphosphine or oleylamine). 9,10,15,20,[22][23][24][25][26][27][28][29][30][31][32] Typically, Se 0 is used as selenide precursor in these syntheses but sometimes rather exotic Se precursors are introduced to achieve ne control over the nucleation and growth of AISe QDs, such as bis(trimethylsilyl)selenide, 33 cyclohexeno-selenodiazole, 21,30 or Li[N(SeMe 3 ) 2 ]. 34 In the latter case, both composition and size of the AISe QDs can be independently varied resulting in "core" AISe and "core/shell" AISe/ZnSe QDs with a size from 2.4 nm to around 7 nm and three distinctly different compositions, Ag 3 -In 5 Se 9 , AgIn 3 Se 5 , and AgIn 11 Se 17 , while a top PL QY of 73% is observed for Ag 3 In 5 Se 9 cores with relatively thick ZnSe shells.…”

Section: Introductionmentioning

confidence: 99%

Ultra-small aqueous glutathione-capped Ag–In–Se quantum dots: luminescence and vibrational properties

et al. 2020

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Temperature dependent photoluminescence of composition tunable Zn_xAgInSe quantum dots and temperature sensor application

Cited by 39 publications

References 37 publications

Electrochemical Charging Effect on the Optical Properties of InP/ZnSe/ZnS Quantum Dots

Electrochemical Charging Effect on the Optical Properties of InP/ZnSe/ZnS Quantum Dots

Surface Plasmon Enhanced Fluorescence Temperature Mapping of Aluminum Nanoparticle Heated by Laser

Ultra-small aqueous glutathione-capped Ag–In–Se quantum dots: luminescence and vibrational properties

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