Phase evolution, powder morphology and photoluminescence exploration of borohydride derived red-emitting Eu3+-doped ZnO nanophosphors

2021 ◽  
Vol 133 ◽  
pp. 105969
Author(s):  
Rahul Singh ◽  
Abhishek King ◽  
Bibhuti B. Nayak
Keyword(s):  
Phase Evolution ◽  
Powder Morphology ◽  
Doped Zno

scholarly journals Ionic and Electronic Conductivities of Lithium Argyrodite Li6PS5Cl Electrolytes Prepared via Wet Milling and Post-Annealing

2021 ◽  
Vol 9 ◽  
Author(s):  
Jae Min Lee ◽  
Young Seon Park ◽  
Ji-Woong Moon ◽  
Haejin Hwang
Keyword(s):  
Coulombic Efficiency ◽  
Electronic Conductivity ◽  
Ionic Conductivities ◽  
Phase Evolution ◽  
Milling Process ◽  
Wet Milling ◽  
Powder Morphology ◽  
Post Annealing ◽  
Electronic Conductivities ◽  
Solid State Cell

Lithium argyrodite Li6PS5Cl powders are synthesized from Li2S, P2S5, and LiCl via wet milling and post-annealing at 500°C for 4 h. Organic solvents such as hexane, heptane, toluene, and xylene are used during the wet milling process. The phase evolution, powder morphology, and electrochemical properties of the wet-milled Li6PS5Cl powders and electrolytes are studied. Compared to dry milling, the processing time is significantly reduced via wet milling. The nature of the solvent does not affect the ionic conductivity significantly; however, the electronic conductivity changes noticeably. The study indicates that xylene and toluene can be used for the wet milling to synthesize Li6PS5Cl electrolyte powder with low electronic and comparable ionic conductivities. The all-solid-state cell with the xylene-processed Li6PS5Cl electrolyte exhibits the highest discharge capacity of 192.4 mAh·g−1 and a Coulombic efficiency of 81.3% for the first discharge cycle.

High Rate Deposition of Al-doped ZnO (AZO) by Reactive Sputtering (1); Unipolar Pulsing with Plasma Emission Control

2008 ◽  
Author(s):  
Yuzo Shigesato ◽  
Kento Hirohata ◽  
Yasutaka Nishi ◽  
Nobuto Oka ◽  
Yasushi Sato ◽  
...  
Keyword(s):  
Emission Control ◽  
Reactive Sputtering ◽  
High Rate ◽  
Plasma Emission ◽  
Doped Zno

Workfunction of Al-Doped ZnO Films Deposited by Atomic Layer Deposition

2018 ◽  
Author(s):  
Peter George Gordon ◽  
Goran Bacic ◽  
Gregory P. Lopinski ◽  
Sean Thomas Barry
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Atomic Ratio ◽  
Aluminum Concentration ◽  
Zno Films ◽  
Transparent Conductor ◽  
Kelvin Probe ◽  
Layer Deposition ◽  
Earth Abundant ◽  
Doped Zno

Al-doped ZnO (AZO) is a promising earth-abundant alternative to Sn-doped In<sub>2</sub>O<sub>3</sub> (ITO) as an n-type transparent conductor for electronic and photovoltaic devices; AZO is also more straightforward to deposit by atomic layer deposition (ALD). The workfunction of this material is particularly important for the design of optoelectronic devices. We have deposited AZO films with resistivities as low as 1.1 x 10<sup>-3</sup> Ωcm by ALD using the industry-standard precursors trimethylaluminum (TMA), diethylzinc (DEZ), and water at 200<sup>◦</sup>C. These films were transparent and their elemental compositions showed reasonable agreement with the pulse program ratios. The workfunction of these films was measured using a scanning Kelvin Probe (sKP) to investigate the role of aluminum concentration. In addition, the workfunction of AZO films prepared by two different ALD recipes were compared: a “surface” recipe wherein the TMA was pulsed at the top of each repeating AZO stack, and a interlamellar recipe where the TMA pulse was introduced halfway through the stack. As aluminum doping increases, the surface recipe produces films with a consistently higher workfunction as compared to the interlamellar recipe. The resistivity of the surface recipe films show a minimum at a 1:16 Al:Zn atomic ratio and using an interlamellar recipe, minimum resistivity was seen at 1:19. The film thicknesses were characterized by ellipsometry, chemical composition by EDX, and resistivity by four-point probe.<br>

Chemical Availability of Bromide Dictates CsPbBr3 Nanocrystal Growth

2019 ◽  
Author(s):  
Je-Ruei Wen ◽  
Benjamin Roman ◽  
Freddy Rodriguez Ortiz ◽  
Noel Mireles Villegas ◽  
Nicholas Porcellino ◽  
...  
Keyword(s):  
Reaction Time ◽  
Growth Mechanism ◽  
Chemical Control ◽  
Critical Role ◽  
Phase Evolution ◽  
Detailed Understanding ◽  
Semiconductor Nanocrystal ◽  
Nanocrystal Growth ◽  
Chemical Availability

Lack of detailed understanding of the growth mechanism of CsPbBr3 nanocrystals has hindered sophisticated morphological and chemical control of this important emerging optoelectronic material. Here, we have elucidated the growth mechanism by slowing the reaction kinetics. When 1-bromohexane is used as an alternative halide source, bromide is slowly released into the reaction mixture, extending the reaction time from ~3 seconds to greater than 20 minutes. This enables us to monitor the phase evolution of products over the course of reaction, revealing that CsBr is the initial species formed, followed by Cs4PbBr6, and finally CsPbBr3. Further, formation of monodisperse CsBr nanocrystals is demonstrated in a bromide-deficient and lead-abundant solution. The CsBr can only be transformed into CsPbBr3 nanocubes if additional bromide is added. Our results indicate a fundamentally different growth mechanism for CsPbBr3 in comparison with more established semiconductor nanocrystal systems and reveal the critical role of the chemical availability of bromide for the growth reactions.<br>

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