Alleviating luminescence concentration quenching in lanthanide doped CaF2 based nanoparticles through Na+ ion doping

2018 ◽  
Vol 47 (22) ◽  
pp. 7534-7540 ◽  
Author(s):  
Bing Xu ◽  
Dongyu Li ◽  
Zhen Huang ◽  
Chunliang Tang ◽  
Wenhao Mo ◽  
...  

Optimal doping concentration of Nd3+ shifts from 10 mol% to 30 mol% through Na+ doping, along with an ∼32 times NIR brightness increase.

2009 ◽  
Vol 60-61 ◽  
pp. 84-88 ◽  
Author(s):  
Xiao Wei Liu ◽  
Xue Bin Lu ◽  
Rong Yan Chuai ◽  
Chang Zhi Shi ◽  
Ming Xue Huo ◽  
...  

The gauge factor and nonlinearity of 80nm polysilicon nanofilms with different doping concentration were tested. The experimental results show that, from 8.1×1018cm-3 to 2.0×1020cm-3, the gauge factors first increase then decrease, which like the common polysilicon films (thickness is larger than 100nm). From 2.0×1020cm-3 to 7.1×1020cm-3, the gauge factors do not change with doping concentration almost, which can be explained by tunneling piezoresistive theory. When doping concentration is low than 4.1×1019cm-3, the nonlinearities are big, and the nonlinearities become small when doping concentration is high than 4.1×1019cm-3. The nonlinearity is related to the occupied condition of trapping states in grain boundary. The longitudinal gauge factor and nonlinearity are smaller than transverse ones. Take the gauge factor and nonlinearity both into consideration, the optimal doping concentration should be 4.1×1019cm-3. The conclusions are very useful for design and fabrication of polysilicon nanofilms piezoresistive sensor.


2012 ◽  
Vol 100 (19) ◽  
pp. 193509 ◽  
Author(s):  
William G. Vandenberghe ◽  
Anne S. Verhulst ◽  
Kuo-Hsing Kao ◽  
Kristin De Meyer ◽  
Bart Sorée ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3066
Author(s):  
Yongbo Li ◽  
Guangyu Han ◽  
Hongyan Zou ◽  
Li Tang ◽  
Honggang Chen ◽  
...  

Incorporating with inhomogeneous phases with high electroluminescence (EL) intensity to prepare smart meta-superconductors (SMSCs) is an effective method for increasing the superconducting transition temperature (Tc) and has been confirmed in both MgB2 and Bi(Pb)SrCaCuO systems. However, the increase of ΔTc (ΔTc = Tc ‒ Tcpure) has been quite small because of the low optimal concentrations of inhomogeneous phases. In this work, three kinds of MgB2 raw materials, namely, aMgB2, bMgB2, and cMgB2, were prepared with particle sizes decreasing in order. Inhomogeneous phases, Y2O3:Eu3+ and Y2O3:Eu3+/Ag, were also prepared and doped into MgB2 to study the influence of doping concentration on the ΔTc of MgB2 with different particle sizes. Results show that reducing the MgB2 particle size increases the optimal doping concentration of inhomogeneous phases, thereby increasing ΔTc. The optimal doping concentrations for aMgB2, bMgB2, and cMgB2 are 0.5%, 0.8%, and 1.2%, respectively. The corresponding ΔTc values are 0.4, 0.9, and 1.2 K, respectively. This work open a new approach to reinforcing increase of ΔTc in MgB2 SMSCs.


2021 ◽  
Author(s):  
Lijuan Wu ◽  
Haifeng Wu ◽  
Jinsheng Zeng ◽  
Xing Chen ◽  
Shaolian Su

Abstract A stepped split triple-gate SOI LDMOS with P/N strip (P/N SSTG SOI LDMOS) is proposed, which has ultralow specific on-resistance (Ron,sp) and low switching losses. The proposed device has a triple-gate (TG) and stepped split gates (SSGs). P strip, N-drift and oxide trench are alternately arranged in the Z direction. Meanwhile, the SSGs are located in the oxide trench of the N-drift region and are distributed in steps. Firstly, the TG increases the channel width (Wch) and has the effect of modulating current distribution, resulting in lower Ron,sp and higher transconductance (gm). Secondly, the SSGs serve as the field plate to assist the depletion of the N-drift region, increasing the optimal doping concentration of the N-drift region (Nd-opt) and further reducing the Ron,sp. Moreover, the SSGs also have the effect of modulating the electric field distribution to maintain a high breakdown voltage (BV). Meanwhile, gate-drain charge (QGD) and switching losses are reduced on account of the introduction of the SSGs. Thirdly, in the off-state, the P strip and SSGs multidimensional assisted depletion of the N-drift region, which greatly increases the Nd-opt. The highly doped N-drift region provides a low-resistance path for the current, which also further reduces Ron,sp. Compared with triple-gate (TG) SOI LDMOS with almost equal breakdown voltage, the Ron,sp and QGD of P/N SSTG SOI LDMOS are reduced by 62% and 63%, respectively.


2008 ◽  
Vol 368-372 ◽  
pp. 414-416 ◽  
Author(s):  
Xue Jun Wang ◽  
Tie Cheng Lu ◽  
Yue Feng Sun

To determine the optimal doping concentration, a series of Mn:MgAl2O4 were successfully prepared through vacuum-sintering with the highest doping concentration up to 35%. Samples with a low doping concentration exhibit a light green color. When the doping concentration increases, its color becomes deeper and deeper and when the doping concentration reaches 14%, their colors become brown and deeper brown when their concentrations further increase. The crystal phases of the samples were manifested by XRD measurements and their photoluminescence properties were studied. Combined with phase analysis, optimal doping concentration of transparent ceramics has been determined. In addition, the mechanism for fluorescence of Mn:MgAl2O4 transparent ceramics has also been discussed.


2015 ◽  
Vol 815 ◽  
pp. 301-303
Author(s):  
Jing Jing Ru ◽  
Mei Zhen Zhou ◽  
Bing Zhao ◽  
Gui Yang Yan ◽  
Shao Ming Ying

A series of novel reddish-orange phosphors Ca3Y2-xSmxWO9were synthesized by solid-state method and characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and photoluminescence (PL) spectra. The results showed that these phosphors are tetragonal structures. The optimum calcining temperature was 1100°C, and the sintering time was 3h. The results demonstrated that the optimal doping concentration of Sm3+in Ca3Y2WO9was about 1 mol%. The main emission line was4G5/2→6H7/2transition of Sm3+at 593nm, and showed intense reddish-orange.


2014 ◽  
Vol 63 (8) ◽  
pp. 087801
Author(s):  
Li Wei ◽  
Chen Chang-Shui ◽  
Wei Jun-Xiong ◽  
Han Tian ◽  
Liu Song-Hao

2015 ◽  
Vol 742 ◽  
pp. 748-752
Author(s):  
Zai Jun Cheng ◽  
Chuan Wen Huang ◽  
Peng Zhou

A theoretical model of Si-based P-N junction isotope microbattery’s electrical output was demonstrated. According to the model, electrical output performance of a 1*1 mm2Si-based isotope microbattery under the irradiation of a 1 mCi63Ni source was simulated. The optimal doping concentration was obtained when the microbattery had the maximum output power density of 0.95 nW/cm2.


2019 ◽  
Vol 214 ◽  
pp. 116543 ◽  
Author(s):  
André L. Moura ◽  
Lauro J.Q. Maia ◽  
Vladimir Jerez ◽  
Anderson S.L. Gomes ◽  
Cid B. de Araújo

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