Direct defluorinative amidation-hydrolysis reaction of gem-difluoroalkenes with N,N-dimethylformamide, and primary and secondary amines

Article abstract of DOI:10.1039/C8OB02322K

A novel and efficient method for the synthesis of arylacetamides by the reactions of gem-difluoroalkenes with N,N-dialkylformamides, and primary and secondary amines with the assistance of KOtBu and water was developed.

Full text of DOI:10.1039/C8OB02322K

Journal of
Materials Chemistry C
View Article Online
View Journal | View Issue
PAPER
Synthesis, optical properties and application of
Y7O6F9:Er3+ for sensing the chip temperature of a
light emitting diode
Cite this: J. Mater. Chem. C, 2018,
6, 13352
Deyin Wang, * Pengpeng Zhang, Qiang Ma, Jiachi Zhang * and
Yuhua Wang
*
Submicron-sized Er3+ doped Y7O6F9 phosphors were synthesized via the precipitation method and a
subsequent annealing process. The influence of the Er3+ doping concentrations and the heating
temperature on the luminescence of Y7O6F9:Er3+ was investigated under the excitation of the Er3+ 4G11/2
level at 378 nm. Upon raising the Er3+ doping concentration, both the intensity and lifetime of the Er3+
4
green emission at 547 nm originating from S3/2
-
4I15/2 decrease, which is proved to be caused by
energy transfer via cross relaxation between two neighboring Er3+ ions. The thermal sensing properties
2
of Y7O6F9:Er3+ were evaluated using the temperature dependent intensity ratio between the H11/2–4I15/2
4
and S3/2–4I15/2 transitions of Er3+ under 378 nm excitation. The experimental results show that the
thermal sensitivity decreased with an increase in the Er3+ doping content, which is caused by the
increased energy transfer probability among Er3+. The increased energy transfer of Er3+ reduces
Received 21st October 2018,
Accepted 26th November 2018
2
the thermalized population of Er3+ in the H11/2 levels, which in turn decreases the thermal sensitivity.
DOI: 10.1039/c8tc05307c
The applicability of Er3+ doped Y7O6F9 as a thermal sensor was demonstrated by measuring the chip
rsc.li/materials-c
temperature of a 1 W InGaN type near-ultraviolet light emitting diode (n-UV LED).
the temperature. However, a careful look at the existing literature
reveals that the previously reported Er3+-based thermal sensor
1. Introduction
Accurate temperature measurement is important in many mainly utilized the up-conversion (anti-stokes luminescence)
applications, and temperature measurement at the micro/nano luminescence of Er3+,12–16 and a few works examined the thermal
scale is a particularly challenging task, because measuring the sensibility by using the Stokes luminescence from Er3+. It is well
temperature in the field, such as in intracellular or micro/nano known that the up-conversion luminescence is a non-linear
electronics is impractical when using a conventional thermo- process and generally has a low efficiency (the efficiency is
meter.1–5 To solve this problem, different temperature measurement strongly dependent on the power of the incident light).10 Apart
techniques have been developed, including nanolithographic from the low efficiency of the up-conversion, the thermal effect
thermometry, the scanning thermal microscope method, the caused by high powered near infrared light excitation (e.g.
resistance thermometry technique, optical techniques, and so 980 nm) may make the measured temperature deviate from the
forth.6–8 Among these different techniques, optical temperature actual temperature.11,12 On the contrary, the efficiency of the
sensors based on the fluorescence intensity ratio (FIR) technique Stokes luminescence is independent of the excitation power and
have attracted great attention,2,9–21 as this kind of sensor has the the thermal effect caused by the excitation light in Stokes
advantages of a rapid response time and immunity to a harsh luminescence can be ignored. Meanwhile, whether or not the
environment when compared to traditional contact thermo- sensor utilizes the up-conversion or Stokes luminescence, host
meters.2,10,11 Er3+ is commonly used in the above mentioned materials with a low phonon energy are preferred, as such host
temperature sensors,12–16 because the two thermally coupled materials can depress the multiphonon relaxation process, result-
2H11/2 and 4S3/2 levels of Er3+ give an intense green emission and ing in a higher luminescence efficiency from the luminescent
their relative emission shows an obvious change depending on center, which is beneficial for the accuracy of the measurement.
In this work, we synthesized different concentrations of Er3+
doped Y7O6F9 via a co-precipitation method, and investigated
National & Local Joint Engineering Laboratory of Light-conversion Materials and
the effects of the Er3+ doping concentrations on the luminescence
Technology, School of Physical Science and Technology, Lanzhou University,
and thermal sensitivity of Y7O6F9:Er3+ under excitation of the Er3+
Lanzhou 730000, China. E-mail: wangdy@lzu.edu.cn, zhangjch@lzu.edu.cn,
wyh@lzu.edu.cn
4G11/2 level at 378 nm. Finally, the potential use of Y7O6F9:Er3+ as
13352 | J. Mater. Chem. C, 2018, 6, 13352--13358
This journal is ©The Royal Society of Chemistry 2018

View Article Online
Paper
Journal of Materials Chemistry C
an efficient optical temperature sensing material has been
demonstrated by determining the chip temperature of a 1 W
near-ultraviolet light emitting diode (n-UV LED).
2. Experimental
2.1 Materials and synthesis
The raw materials for Y2O3 (99.9%), Er2O3 (99.9%) and NH4F
(99.99%) were purchased from Aladdin Chemical reagent company
and used without further purification.
Powder samples Y7O6F9:xEr3+ (x = 0, 1%, 3% and 5%) were
prepared using a co-precipitation method. The Er3+ doping
concentration refers to the nominal concentration in mol%.
In detail, stock solutions of 0.5 mmol mlꢀ1 Y(NO3)3 and
0.005 mmol mlꢀ1 Er(NO3)3 were prepared in advance by dis-
solving Y2O3 and Er2O3 in hot nitric acid, and the residual nitric
acid was evaporated by heating. The weighed trivalent lanthanide
nitrate solution was added dropwise into the NH4F solution by
using a separatory funnel under continuous stirring. The resulting
white precipitate was separated by centrifugation and dried at
80 1C in an oven for 12 h. Finally, the precipitate was annealed
at 600 1C for 2 h followed by 800 1C for 2 h in air with
intermediate grounding.
2.2 Characterization
The X-ray diffraction (XRD) data were measured using a Bruker
D2 Phaser powder X-ray diffractometer. The photoluminescence (PL)
and photoluminescence excitation (PLE) spectra were measured
using a Fluorlog-3 spectrophotometer. The decay curves and
quantum efficiency were measured using the FLS 980 spectro-
meter. Scanning electron microscopy (SEM) was recorded by
using the Hitachi S-4800 electron microscope. Transmission
electron microscope (TEM), high-resolution transmission electron
microscope (HRTEM) and selected area electron diffraction (SAED)
images were taken on a JEM-2010 electron microscope. Elemental
mapping was obtained on a TECNAI G2 TF20 electron microscope.
The Er3+ doping concentration in all samples was determined by
using inductively coupled plasma-atomic emission spectrometry
(ICP-AES) (PlasmaQuant 9000). The electroluminescent (EL)
spectrum was measured using an EVERFINE spectrophotometer
with an integral sphere under ambient conditions at room
temperature.
Fig. 1 (a) XRD patterns of the precursor prepared using the precipitation
method and the samples annealed at different temperatures. (b) XRD
patterns of Y7O6F9:xEr3+
.
The as-fabricated precursor dried at 80 1C is identified as
YF3ꢁ1.5NH3 (JCPDS No. 281449). When the precursor is subject
to post-annealing at 600 1C, it transforms into the orthorhombic
phase YF3 (JCPDS No. 701935). With further increasing of the
post annealing temperature to 800 1C, the final product becomes
an orthorhombic phase Y7O6F9 (JCPDS No. 801126), and when
the post annealing temperature is increased up to 1000 1C,
Y7O6F9 is converted into a mixture of YOF (JCPDS No. 712100)
and Y2O3 (JCPDS No. 895592). Based on the XRD results, the Er3+
doped precursor samples were firstly annealed at 600 1C then at
800 1C with intermediate grinding to obtain the pure phase of
Y7O6F9. Fig. 1b shows the XRD patterns of Y7O6F9 doped with
3. Results and discussion
3.1 Morphology and phase identification
The structure of Y7O6F9 consists of a single YO+ layer sand- different concentrations of Er3+. The diffraction patterns for all of
wiched between Fꢀ layers. There are two coordination environ- the Er3+ doped samples were found to be identical to the
ments for Y3+ in Y7O6F9, viz. one site is coordinated by four O2ꢀ and reference data (JCPDS No. 801126) and no other impurities were
three Fꢀ anions, the other site is coordinated by four O2ꢀ and four observed, indicating the introduction of Er3+ did not change the
Fꢀ anions.22 In view of same valence and similar ionic radius of Er3+ crystal structure Y7O6F9. In addition, because the ionic radius of
(r = 89 pm) and Y3+ (90 pm),23 the Er3+ ions are expected to occupy Er3+ (r = 89 pm) is very close to that of Y3+ (r = 90 pm)23 and owing
the Y sites in Y7O6F9. Fig. 1a shows the XRD patterns of the to the successful substitution of Y3+ by Er3+, the diffraction
precursor prepared using the precipitation method and the pattern demonstrated almost has no changes upon doping with
samples after being annealed at different temperatures for 2 h. Er3+. To give the quantitative data for the doping amount of Er3+
This journal is ©The Royal Society of Chemistry 2018
J. Mater. Chem. C, 2018, 6, 13352--13358 | 13353

View Article Online
Journal of Materials Chemistry C
Paper
Table 1 Nominal and measured Er3+ doping concentrations in different
samples
Nominal concentration Measured concentration
Sample
of Er3+(wt%)
of Er3+ (wt%)
Y7O6F9:0.5 mol%Er3+ 0.66
Y7O6F9:1 mol%Er3+ 1.30
Y7O6F9:3 mol%Er3+ 3.88
Y7O6F9:5 mol%Er3+ 6.38
0.63
1.27
3.75
6.51
Fig. 3 Elemental mapping of Y7O6F9:1%Er3+
.
Fig. 2 SEM (a), TEM and HRTEM images (b and c), and SAED pattern (d) for
Y7O6F9:1%Er3+
.
in each sample, spectral analysis using ICP-AES technique was
conducted. The obtained results are listed in Table 1, from which
it can be seen that the measured Er3+ concentration in each
sample was close to the corresponding nominal concentration.
Fig. 2a–d shows the SEM, TEM and HRTEM images together
with the SAED pattern of Y7O6F9:1%Er3+, respectively. It can be
seen from Fig. 2a and b that the obtained sample has an
irregular shape with the presence of agglomerates, which are
probably caused by the subsequent high temperature calcinations.
From some of separated particles presented in Fig. 2a and b, it can
be seen that the agglomerates are composed of particles with a size
of around 500–700 nm. The HRTEM image (Fig. 2c) clearly exhibits
lattice fringes with an interval of 0.315 nm, corresponding to
the (171) lattice plane of the orthorhombic phase Y7O6F9. The
well-resolved lattice fringes indicate the high crystallinity of the
obtained sample. The bright diffraction spots in the SAED pattern
(Fig. 2d) further reveal the high crystallinity of Y7O6F9:Er3+, and
this is probably because the area of the sample selected by the
aperture in the TEM contains only a few crystals, the SAED pattern
is made up of spots. The elemental mapping of Y7O6F9:1%Er3+ is
shown Fig. 3, which clearly indicates the uniform distribution of
the four elements (F, O, Y, and Er) over the whole particle.
Fig. 4 (a) PLE and (b) PL spectra for Y7O6F9:xEr3+
.
3.2 Concentration dependent luminescence of Y7O6F9:Er3+
4
to the transitions of Er3+ from its ground state I15/2 to its excited
Fig. 4 shows the PLE and PL spectra of Y7O6F9 doped with states G9/2/2K15/2, G11/2, F5/2, F7/2 and H11/2, respectively.18,24,25
different amounts of Er3+. All of the PLE spectra are same Upon the strongest absorption at 378 nm, corresponding to the Er3+
except for the intensity. The sharp absorption peaks at 365, 378, 4I15/2 - 4G11/2 transition, all of the emission spectra for the samples
450, 490 and 520 nm observed in the PLE spectra are ascribed are composed of an intense green emission at 547 nm and a weaker
4
4
4
4
2
13354 | J. Mater. Chem. C, 2018, 6, 13352--13358
This journal is ©The Royal Society of Chemistry 2018

View Article Online
Paper
Journal of Materials Chemistry C
red emission at 670 nm, originating from the H11/2/4S3/2 - I15/2 two sites decrease (the average lifetime of the Er3+ emission at
and 4F9/2 - 4I15/2 transitions of Er3+, respectively.21,22 The overall 547 nm decreases from 173 ms at x = 0.5% to 29 ms at x = 5%),
emission intensity increases with an increased Er3+ doping which is caused by the increased energy transfer among the
concentration because of the increased number of luminescent Er3+–Er3+ and Er3+-defects.
2
4
centers. When the Er3+ doping concentration exceeds 1%, its
To further clarify the energy transfer process in the Er3+doped
emission intensity starts to decrease owing to the concentration Y7O6F9, the Vis-NIR-IR emission spectra for Y7O6F9:xEr3+ excited
quenching effect caused by the energy transfer. The internal at 378 nm were measured (Fig. 6a). The near-infrared emission at
quantum efficiency of the 1%Er3+ doped sample was determined around 1000 nm and the infrared emission at around 1550 nm
to be 40.1%.
were assigned to transitions from the excited states 4I11/2 and 4I13/
To provide further evidence for the occurrence energy transfer 2 to the ground state 4I15/2 of Er3+ ions, respectively.24,25 When the
in Y7O6F9:xEr3+, the luminescence decay curves monitoring the Er3+ doping contents are increased, the visible green emission at
green emission at 547 nm under 378 nm excitation were 547 nm deceases while the infrared emissions at 1000 nm and
measured and the results are shown in Fig. 5. The decay curves 1550 nm increase. This phenomena can be rationalized by a cross
were normalized on the maximum intensity and plotted as a relaxation energy transfer between the two neighboring Er3+ ions
semi-logarithmic plot. The decay curves were fitted using a via (Er3+ 4 3/2 - 4I13/2:Er3+ 4 15/2 - 4I11/2) as indicated by the pink
S I
double exponential function:26
dotted line shown in Fig. 6b. Owing to the energy migration
process, the population of the Er3+ in 4S3/2 state decreases, while
I(t) = A1 exp(ꢀt/t1) + A2 exp(ꢀt/t2)
(1)
4
4
that in I13/2 and I11/2 increases, as a consequence, the green
4
emission from the S3/2 state decreases while the two infrared
In which I is the luminescence intensity and A1 and A2 are
the fractional contributions of the decay lifetimes t1 and t2. The
average lifetime t is determined by:
emissions increase accordingly.24,25 These results suggest that
the cross relaxation process between the two nearby Er3+ is the
4
main depopulation process of the Er3+ at S3/2 state.
2
2
A1 ꢂ t1 þ A2 ꢂ t2
A1 ꢂ t1 þ A2 ꢂ t2
t ¼
(2)
The fitting parameters of each decay curve are summarized
in Table 2. The two decay components correspond to Er3+ in two
different sites in Y7O6F9. When the Er3+ doping concentrations
are increased, the lifetimes of both of the Er3+ emissions from the
Fig. 5 Decay curves (dotted lines) for the Er3+ emission at 547 nm in
Y7O6F9:xEr3+ under excitation at 378 nm. The solid lines are the fitted
results.
Table 2 Fitting parameters for the decay curve for Y7O6F9:xEr3+ under
excitation at 378 nm
x (%)
A1
t1 (ms)
A2
t2 (ms)
T (ms)
R2
0.5
1
3
0.393
0.511
0.842
0.925
0.058
0.045
0.025
0.017
0.607
0.488
0.158
0.075
0.196
0.177
0.090
0.067
0.173
0.149
0.051
0.029
0.9997
0.9996
0.9996
0.9995
Fig. 6 (a) Vis-NIR-IR PL spectra for Y7O6F9:xEr3+ under excitation at
378 nm. (b) Energy level diagram for Er3+ and the proposed luminescence
process under excitation in the Er3+ 4G11/2 level.
5
This journal is ©The Royal Society of Chemistry 2018
J. Mater. Chem. C, 2018, 6, 13352--13358 | 13355

View Article Online
Journal of Materials Chemistry C
Paper
3.3 Thermal sensing performance of Y7O6F9:Er3+
To examine the application potential of Er3+ doped Y7O6F9 for
determining temperature, the dependence of the Er3+ green
2
4
emission originating from the H11/2/4S3/2 - I15/2 transitions
on temperature in a temperature region from 300 to 550 K was
measured. Temperature sensing using Er3+ is based on the
measurement of the intensity ratio between the luminescence from
2
4
two closely separated energy levels, H11/2 and S3/2, whose relative
population is determined by the Boltzmann distribution:16–19
FIR = I522nm/I547nm = C exp(ꢀDE/kT)
(3)
In which I522nm and I547nm are the integrated intensities of
2
4
the H11/2
- -
4I15/2 and S3/2 4I15/2 transitions of Er3+,
Fig. 8 Thermal sensitivity of Y7O6F9:xEr3+ in the temperature range from
300 to 550 K. The points show the experimental values and the solid lines
show the theoretical values.
respectively, C is a constant, DE is the energy difference between
4
2H11/2 and S3/2, and k is the Boltzmann constant.16–19 Fig. 7a
illustrates the green emission spectra obtained upon raising the
temperature for the lowest Er3+ concentration, the 0.5% doped
sample, which was normalized to the strongest intensity of the
increasing temperature, which can be explained using eqn (3).
4
4S3/2 - I15/2 emission peak to better show the intensity variation
2
Fig. 7b shows the dependence of the FIR between the H11/2
-
from the 2H11/2 and 4S3/2 levels. It can be seen from Fig. 7a that the
intensity ratio between the two levels gradually increases with the
4I15/2 and S3/2 - I15/2 emission bands of Er3+ on the absolute
temperature for the different concentrations of Er3+ doped Y7O6F9. It
can be seen from Fig. 7b that the FIR increases slowly in the doped
sample with a higher concentration of Er3+, which is considered to
4
4
be caused by the re-absorption of Er3+. There is an obvious spectral
2
overlap between the emission H11/2
-
4I15/2 and absorption
4I15/2 - 2H11/2 of Er3+ in the 500–530 nm region (see Fig. 4a and b).
When the Er3+ doping concentrations and heating temperature
increase, the distance between the Er3+ ions is reduced, and as
a consequence of thermal assisted energy transfer, re-absorption
among the neighboring Er3+ is increased. Therefore, at a higher
given temperature, the FIR is decreased with the increasing Er3+
doping concentration. In addition, the dependence of the FIR on
temperature for the different Er3+ doped samples can be well
fitted by using eqn (3), and the corresponding fitted function is
listed in Fig. 7b. In all samples, the DE determined from the
fitting results is close (DE0.5% = 730 cmꢀ1, DE1% = 726 cmꢀ1
,
DE3% = 690 cmꢀ1 and DE5% = 670 cmꢀ1) to that determined from
the emission spectra (DE = 766 cmꢀ1).
For optical temperature sensing applications, sensitivity (S)
is an important index that reflects the performance of the
obtained sensor, and the sensitivity is defined as the rate of
change of the FIR with temperature:16–19
dFIR
DE
kT2
S ¼
¼ FIR ꢁ
(4)
dT
Fig. 8 shows the dependence of the sensitivity (S) of
Y7O6F9:xEr3+ on the temperature from 300 to 550 K. The solid
line is the theoretical line based on eqn (4). It is observed that a
maximum sensitivity of 0.0050 Kꢀ1 was achieved at 498 K in the
lowest Er3+ doped sample, and that the value was almost
1.7 times higher compared to the highest Er3+ doped sample.
Fig. 7 (a) Temperature dependent green emission spectra of Y7O6F9:0.5%
Er3+. (b) Dependence of FIR on temperature in Y7O6F9:xEr3+. The intensity of the
3.4 Demonstration of the temperature measurement
To demonstrate the potential application of Y7O6F9:Er3+ as a
temperature sensing material, Y7O6F9:Er3+ was used to determine
Er3+ 2
H
11/2 - 4I15/2 transition was integrated from 510 nm to 540 nm, while that
of the 4S3/2
-
4I15/2 transition was integrated from 540 nm to 580 nm.
13356 | J. Mater. Chem. C, 2018, 6, 13352--13358
This journal is ©The Royal Society of Chemistry 2018

View Article Online
Paper
Journal of Materials Chemistry C
cross relaxation process between two neighboring Er3+ via (Er3+
4S3/2 - 4I13/2:Er3+ 4 15/2 - 4I11/2) and the increased re-absorption of
I
Er3+ owing to the large spectral overlap between the emission and
absorption green bands from Er3+, respectively. As a proof of
concept, Y7O6F9:1%Er3+ was used to determine the temperature
of a LED chip. The chip temperature of a 1 W InGaN type n-UV
LED chip operating at U = 3.5 V and I = 300 mA was determined
to be about 95 1C.
Conflicts of interest
There are no conflicts to declare.
Acknowledgements
Fig. 9 EL spectrum of the LED coated with Y7O6F9:1%Er3+ and operated at U =
3.5 V and I = 300 mA. The left upper inset is the emission spectrum of the LED,
and the right upper inset photographs are the naked LED, the LED coated with
Y7O6F9:1%Er3+ without and with a driven current (300 mA), respectively.
The authors grateful acknowledge support for this research
from the National Natural Science Foundation of China (grant
no. 51602137) and Lanzhou Chengguan Science and Technology
Bureau (grant no. 2018KJGG0097).
the chip temperature of a 1 W InGaN type n-UV LED (epileds
products; wavelength peak: 375–380 nm; chip size: 40 ꢂ 40 mil;
forward voltage: 3.4–3.8 V). In a practical experiment, a few
milligrams of Y7O6F9:1%Er3+ was glued just on the top of the
LED chip (see inset in Fig. 9). The n-UV LED chip was selected
because it is can be used as either the heater or light source to
excite the Y7O6F9:1%Er3+ with the strongest absorption at 378 nm
(Fig. 4a). This selection greatly simplified the experimental
procedure, because if the selected LED was unable to excite
Y7O6F9:Er3+, then light from a spectrometer would need to be
used, however, the small size of the chip makes measurement
difficult. In the meantime, an appropriate electrical current must
be applied to allow the LED to work. Both of these factors will
make the measurement of the temperature complicated. The EL
spectrum of the chip is shown in the right upper inset in Fig. 9.
As the EVERFINE spectrophotometer used for the EL spectra
measurement does not show a response below 380 nm, the
emission spectrum of the LED was measured using a Fluorlog-3
spectrophotometer and is presented separately. Fig. 9 shows the
EL spectrum of the 1 W LED coated with Y7O6F9:1%Er3+ and
operated at U = 3.5 V and I = 300 mA, and emission color of
Y7O6F9:1%Er3+ is shown in the inset. From the reference data
presented in Fig. 7b and the EL spectrum shown in Fig. 9, the
temperature of the chip operated at U = 3.5 V and I = 300 mA was
determined to be about 95 1C.
Notes and references
´
´
´
1 P. Haro-Gonzalez, L. Martınez-Maestro, I. R. Martın,
´
´
J. Garcıa-Sole and D. Jaque, Small, 2012, 8, 2652–2658.
2 R. G. Geitenbeek, P. Tim Prins, W. Albrecht, A. van Blaa-
deren, B. M. Weckhuysen and A. Meijerink, J. Phys. Chem. C,
2017, 121, 3503–3510.
´
3 F. Vetrone, R. Naccache, A. Zamarron, A. Juarranz de la
´
´
Fuente, F. Sanz-Rodrıguez, L. M. Maestro, E. Martın Rodri-
´
guez, D. Jaque, J. G. Sole and J. A. Capobianco, ACS Nano,
2010, 4, 3254–3258.
4 M. A. Bennet, P. R. Richardson, J. Arlt, A. McCarthy,
G. S. Buller and A. C. Jones, Lab Chip, 2011, 100, 3821–3828.
5 E. Saidi, N. Babinet, L. Lalouat, J. Lesueur, L. Aigouy, S. Volz,
J. Labeguerie-Egea and M. Mortier, Small, 2011, 7, 259–264.
6 J. Lee and N. A. Kotov, Nano Today, 2007, 2, 48–51.
7 Y. Yue and X. Wang, Nano Rev., 2012, 3, 11586–11596.
8 C. Yan, J. Wang and P. Lee, ACS Nano, 2015, 9, 2130–2137.
9 Y. Wu, J. Liu, J. Ma, Y. Liu, Y. Wang and D. Wu, ACS Appl.
Mater. Interfaces, 2016, 8, 14396–14405.
10 L. H. Fischer, G. S. Harms and O. S. Wolfbeis, Angew. Chem.,
Int. Ed., 2011, 50, 4546–4551.
11 J. Cai, L. Zhao, F. Hu, X. Wei, Y. Chen, M. Yin and C. Duan,
Inorg. Chem., 2017, 56, 4039–4046.
12 B. Cao, Y. He, L. Zhang and B. Dong, J. Lumin., 2013, 135, 128–132.
13 A. Pandey, S. Som, V. Kumar, V. Kumar, K. Kumar, V. K. Rai
and H. C. Swart, Sens. Actuators, B, 2014, 202, 1305–1312.
4. Conclusions
In summary, different concentrations of Er3+ doped Y7O6F9 14 H. Suo, C. F. Guo and T. Li, J. Phys. Chem. C, 2016, 120, 2914–2924.
phosphors were prepared through the phase transformation 15 N. HamzaBelkhir, A. Toncelli, A. K. Parchur, E. Alves and
from YF3ꢁ1.5NH3, which was obtained using the co-precipitation
R. Maalej, Sens. Actuators, B, 2017, 248, 769–776.
method, and their luminescence properties were investigated. 16 F. Vetrone, R. Naccache, A. Zamarron, A. J. de la Fuente,
By increasing the Er3+ doping concentration, the lifetime of the
Er3+ green emission at 547 nm was significantly reduced and the
F. Sanz-Rodriguez, L. M. Maestro, E. M. Rodriguez, D. Jaque,
J. G. Sole and J. A. Capobianco, ACS Nano, 2010, 4, 3254–3258.
temperature sensitivity of the Er3+ doped Y7O6F9 decreased 17 S. Zhou, K. Deng, X. Wei, G. Jiang, C. Duan, Y. Chen and
continuously. This was proven to be caused by the increased
M. Yin, Opt. Commun., 2013, 291, 138–142.
This journal is ©The Royal Society of Chemistry 2018
J. Mater. Chem. C, 2018, 6, 13352--13358 | 13357

View Article Online
Journal of Materials Chemistry C
Paper
´
´
18 S. F. Leon-Luis, V. Monteseguro, U. R. Rodrıguez-Mendoza, 22 C. Park and P. Sangmoon, J. Lumin., 2016, 178, 463–469.
´
´
´
I. R. Martın, D. Alonso, J. M. Caceres and V. Lavın, J. Lumin., 23 R. D. Shannon, Acta Crystallogr., Sect. A: Cryst. Phys., Diffr.,
2016, 179, 272–279. Theor. Gen. Crystallogr., 1976, 32, 751–767.
19 S. A. Wade, S. F. Collins and G. W. Baxter, J. Appl. Phys., 24 D. Wang, P. Ma, J. Zhang and Y. Wang, ACS Appl. Energy
2003, 94, 4743–4756. Mater., 2018, 1, 447–454.
20 H. Suo, X. Zhao, Z. Zhang and C. Guo, ACS Appl. Mater. 25 S. Balaji, D. Ghoshab, K. Biswas, A. R. Allu, G. Gupta and
Interfaces, 2017, 9, 43438–43448. K. Annapurna, J. Lumin., 2017, 187, 441–448.
21 H. Suo, X. Zhao, Z. Zhang, R. Shi, Y. Wu, J. Xiang and 26 C. Wang, T. Takeda, O. Kate, R. Xie, K. Takahashi and
C. Guo, Nanoscale, 2018, 10, 9245–9251.
N. Hirosaki, J. Mater. Chem. C, 2016, 4, 10358–10366.
13358 | J. Mater. Chem. C, 2018, 6, 13352--13358
This journal is ©The Royal Society of Chemistry 2018