Spectrally resolved thermoluminescence in electron irradiated AlN submicrocrystals

Accepted Manuscript Spectrally resolved thermoluminescence in electron irradiated AlN submicrocrystals D.M. Spiridonov, I.A. Weinstein, D.V. Chaykin, A.S. Vokhmintsev, YuD. Afonin, A.V. Chukin PII:

S1350-4487(18)30697-8

DOI:

https://doi.org/10.1016/j.radmeas.2019.02.001

Reference:

RM 6062

To appear in:

Radiation Measurements

Received Date: 21 October 2018 Revised Date:

30 January 2019

Accepted Date: 1 February 2019

Please cite this article as: Spiridonov, D.M., Weinstein, I.A., Chaykin, D.V., Vokhmintsev, A.S., Afonin, Y., Chukin, A.V., Spectrally resolved thermoluminescence in electron irradiated AlN submicrocrystals, Radiation Measurements (2019), doi: https://doi.org/10.1016/j.radmeas.2019.02.001. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT

Spectrally resolved thermoluminescence in electron irradiated AlN submicrocrystals

D.M. Spiridonov, I.A. Weinstein, D.V. Chaykin, A.S. Vokhmintsev, Yu.D. Afonin, A.V. Chukin NANOTECH Center, Ural Federal University, Mira street, 19, Ekaterinburg, 620002, Russia

RI PT

[email protected]

Keywords:

SC

aluminum nitride; electron beam; cathodoluminescence; spectrally resolved thermally stimulated

M AN U

luminescence; nitrogen vacancy; aluminum vacancy; oxygen-related center

Abstract:

Aluminum nitride crystals of regular geometric shape and with 0.1 – 2.0 µm size have been synthesized by original gas-phase technique. Using chemical composition analysis, the presence of

TE D

main impurities of oxygen and silicon have been testified. The spectral features of cathodoluminescence (CL) and thermoluminescence (TL) under electron irradiation have been studied in grown AlN. It has been found that the measured CL and TL spectra have an almost

EP

identical form of single wide peak at 420 nm (2.95 eV), which can be approximated by superposition of three Gaussian components – weak 2.04 and 2.46 eV, predominant 2.87 eV. The

AC C

possible origin of observed emissions has been discussed taking independent data into account. It has been found that 2.87 and 2.46 eV recombination processes occurred through electron transitions with participating of impurity ON and oxygen-vacancy centers (VAl-ON). 2.04 eV emission was caused by radiative transition between hole (VAl-ON)-levels and valence band. Analyzing measured three-dimensional TL dependence in AlN microcrystals after 14.6 kGy irradiation, it has been established that the maximum of the TL emission is observed at 420 nm and at a temperature of 345 K. Experimental TL curves have been described numerically in the frame of the general-order kinetic formalism with high accuracy to determine the activation energy

ACCEPTED MANUSCRIPT

EA = 0.58 eV of VN-trap which is responsible supposedly for the thermally stimulated emission observed. Taking calculated values of the kinetic parameters into account, it has been concluded that the recapturing of charge carriers to the indicated vacancy levels is characterized by a high probability in mechanisms of the radiation-stimulated response of AlN microcrystals irradiated with

RI PT

electrons

Introduction

SC

Aluminum nitride based micro- and nanoscale crystalline structures are promising functional media for creating innovative optoelectronic elements, compact luminescent transformers, photon

M AN U

emitters and laser devices for applications in the UV and visible spectral ranges (Taniyasu et al., 2006; Jung et al., 2013; Zhao et al., 2015; Vokhmintsev et al., 2015a; Genji et al., 2016; Weinstein et al., 2016; Shen et al., 2016). A number of papers were devoted to study of luminescence properties in different AlN structures (AlN-Y2O3 ceramics, powder, bulk single crystals, films etc.) and make statements concerning their possible use for solving fundamental and applied problems of

TE D

solid-state dosimetry by means of the thermally and optically stimulated luminescence methods (Trinkler et al., 2007; Bastek, et al., 2009; Berzina, et al., 2009; Weinstein et al., 2012;

EP

Vokhmintsev et al., 2012a, 2012b, 2013; Trinkler and Berzina, 2014a; Choudhary et al., 2014). Despite the high sensitivity to ionizing radiation, these media as storage detectors to be used in

AC C

practice face certain difficulties due to the high fading (Trinkler et al., 2007; Vokhmintsev et al., 2012a; Trinkler and Berzina, 2014a). In turn, they exhibit intensive afterglow immediately after and directly during radiation exposure. This demonstrates the possibility of successfully using them as sensitive elements in devices for express-controlling and analyzing absorbed dose in real time. There are currently numerous methods for synthesis of various structural modifications of aluminum nitride: chloride-assisted growth, carbon nanotube-confined reaction, arc-discharge, silica assisted catalytic growth, vapor-liquid-solid growth, etc. (Liu et al., 2001; Zhang et al., 2001; Tondare et al., 2002; Bickermann et al., 2009; Shen et al., 2013; Choudhary et al., 2014; Afonin et

ACCEPTED MANUSCRIPT

al., 2016). In AlN, as in most related compounds, oxygen and carbon are the main technological, difficult-to-control impurities. Embedding the above atoms in the nitrogen and aluminum sublattices contributes to the occurrence of corresponding vacancies. When exposed to ionizing radiation, the resulting oxygen-vacancy complexes become optically active and exhibit an intense

RI PT

luminescent response in the visible range (Weinstein et al., 2012; Trinkler and Berzina, 2014a). The aforementioned processes are due to the formation of a complex system of energy levels and, even, subbands in the band gap of aluminum nitride (Koppe et al., 2016). This system is formed by

SC

involving point and cluster defects of intrinsic and extrinsic nature, and also provides mutual transfer of captured charge carriers with intense radiative recombination at different temperatures.

M AN U

In this regard, approaches of spectrally resolved thermally stimulated luminescence allow to conduct a detailed analysis of the multistage mechanisms of the thermally activated processes observed. They also give the opportunity to selectively stimulate, excite and study the capture and recombination centers of a certain type. This paper presents the results of the investigation of the cathodoluminescence and spectrally resolved thermally stimulated luminescence caused by oxygen-

EP

with electrons.

TE D

related complexes in submicron AlN crystals synthesized by a gas-phase technique and irradiated

Samples and Experimental Technique

AC C

In this work it was studied the properties of microcrystalline AlN powder, synthesized using a unique setup by the method of gas-phase synthesis with the liquid aluminum treating in an atmosphere of gaseous AlF3 and NH3 (Chaykin et al., 2019). A Sigma VP Carl Zeiss scanning electron microscope (SEM) equipped with an X-max Oxford Instruments Energy Dispersive Detector (EDS) was applied for investigating the powder’s morphological features and chemical composition. X-ray phase analysis was performed on an X’Pert Pro MPD PANalytical diffractometer operated at 40 kV and 30 mA with CuKα radiation, scanned over 2Θ from 20° to

ACCEPTED MANUSCRIPT

90° with a step of 0.05° and time per step 10 s. The observed X-ray diffractogram was fitted with the least squares procedure using Rietveld full profile refinements and PDF-4 database. Cathodoluminescence (CL) spectra were measured using a CLAVI-R pulsed spectroscope on the basis of a RADAN-EXPERT compact electron accelerator (Solomonov et al., 2006). AlN

RI PT

microcrystals were excited at room temperature by pulses having the following characteristics: duration of 2 ns, a frequency of 1 Hz, an average electron energy of 155 ± 5 keV, and a current density of 150 A/cm2. The number of the pulses was ranged within N = 16 ÷ 128. The CL spectra

SC

were detected at 350-750 nm, the accumulation time was 20 ms. The samples were irradiated by the above-mentioned electron beams for excitation thermoluminescence (TL) response. Using standard

M AN U

dosimetric SO PD (F) P-5/50 films the absorbed dose was determined from the change in the induced optical density at a wavelength of 512 nm. The dose was ranged within D = 1.8 ÷ 14.6 kGy.

The thermally stimulated luminescence was recorded using a unique automated setup based on a

TE D

Perkin Elmer LS55 spectrometer and a high-temperature attachment. The samples were preannealed at 770 K followed by exposing to the electrons (D = 14.6 kGy) and then by heating from room temperature to 770 K. The heating rate amounted to r = 0.4 K/s. The experiment used a

EP

spectral gap of 20 nm in the range of 250-650 nm and a scan rate of 25 nm/s. The experimental setup assembled and the measurement technique for three-dimensional TL dependencies in the

AC C

coordinates of “I intensity – λ wavelength – T temperature” are well described in our papers (Vokhmintsev et al., 2014, 2015b). Before numeric fitting procedure the measured CL and TL spectra were corrected on λ2.

Results The SEM image demonstrates (Fig. 1) that the synthesized powder consists of submicroparticles as hexagonal prisms of regular geometric shape and combinations of a prism with a bipyramid with characteristic sizes of 0.1-2.0 µm. The X-ray phase analysis (Fig.1) yields the only AlN crystalline

ACCEPTED MANUSCRIPT

phase with the P63mc wurtzite space group and the following lattice parameters: a = 3.1117 Å and c = 4.9794 Å. The conducted analysis of the chemical composition testified that the particles studied have non-stoichiometry in Al with the ratio Al : N = 0.9 : 1 and atoms of O (1.6 at.%), and Si (0.5 at.%) are the main impurities. No impurity phase inclusions were found in the synthesized

RI PT

samples. Fig. 2 shows the CL spectra measured for the AlN microcrystals. The dependencies involve a wide band with a maximum at 420 ± 5 nm (2.95 eV). It should be noted that the findings obtained

SC

are in complete agreement with data for various structural modifications of aluminum nitride. In particular, a CL peak at 3.0 eV was previously recorded in thin AlN layers doped with silicon

M AN U

(Thapa et al., 2008) and bulk AlN single crystals (Spiridonov et al., 2015). It is worth emphasizing that the shape of the spectra remains unchanged and is radiation dose-independent in the range at hand. In this case, when D is greater than 5.4 kGy, the CL response intensity reaches saturation, See the upper inset in Fig. 2.

Fig. 2 presents also the TL spectra measured at different temperatures. The shapes of the spectral

TE D

dependencies for thermo- and cathodoluminescence almost coincide with each other (See the lower inset with normalized curves). For clarity, Fig. 3 contains an experimental three-dimensional TL

EP

dependence for the irradiated AlN microcrystals. It is a single unstructured peak. It can be seen that the maximum of the TL emission is observed at the band of 420 ± 5 nm and at a temperature of

AC C

345 ± 5 K.

Let us estimate the spectral-kinetic parameters and discuss the features of the observed luminescence in the synthesized microcrystals.

Discussion The CL and TL spectra measured (Fig. 4, red and blue solid lines) were approximated using a superposition of several independent Gaussians. It can be noticed that in both cases the resulting curve describes the experimental data with a high degree of accuracy R2 > 0.999. The calculated

ACCEPTED MANUSCRIPT

values of the resolution parameters are listed in Table 1. Both spectra share a wide peak of G2 with a maximum of 2.87 eV, it is dominant. It should be noted that, in contrast to the studied submicrocrystalline samples, the TL spectra of bulk single crystals after X-ray, UV- and βirradiation are dominated by the emission of 3.43 eV (Soltamov et al., 2011; Weinstein et al., 2012;

RI PT

Vokhmintsev et al., 2012a). In addition, a weak G1 band at 2.04 eV whose intensity is almost 15 times lower than that of G2 is observed for both spectra. The independent spectral components with the equal quantitative

SC

parameters indicate one and the same origin of the optically active centers responsible for the TL and CL emission. Nevertheless, it should be necessarily pointed out that the G3 component with a

M AN U

maximum of 2.46 eV emerges in the TL spectrum at temperatures less than 400 K and is nonobservable in the CL spectra.

Let us analyze the possible nature of the obtained spectral peaks in the luminescence of synthesized microcrystals. In doing so, we will resort to independent data for various structural

TE D

modifications of aluminum nitride. It is known (Pastrňák et al., 1974), that the thermally stimulated emission of AlN:O powders provokes a TL peak of 2.96 eV. According to (Thapa et al., 2008; Shen et al., 2013) CL and PL maxima of 3 eV in silicon doped AlN layers can be generated due to

EP

radiation centers based on aluminum vacancies VAl. The authors revealed that, within the above region, the luminescence intensity increases with rising the Si impurity concentration in the

AC C

samples. This happens because of forming additional VAl-centers. The presence of silicon impurity in our crystals according to chemical analysis data apparently leads to similar effects. The CL band at 3.1-3.2 eV in AlN bulk single crystals and in AlN epilayers is caused by complex defects such as VAl3–-ON (Spiridonov et al., 2015; Koppe et al., 2016). In addition, in (Koyama et al., 2007; Bickermann et al., 2009) it was suggested that the luminescence under discussion arises due to recombination transitions between O-DX centers and complexes involving VAl3–. The paper (Cao et al., 2000) also reports on the band with a maximum of 2.95 eV when investigating PL in AlN nanocrystalline powders. The band was attributed to electron-optical

ACCEPTED MANUSCRIPT

transitions from the shallow level of VN to the ground state of the deep level of the VAl3−-3ON+ complexes. Trinkler and Berzina, 2014b assigned the 3.1-3.2 eV emission in AlN-Y2O3 ceramics to recombination transitions involving donor – acceptor pairs based on (ON–VAl)-complexes and ONtraps.

RI PT

Earlier Weinstein et al., 2012 found that bulk AlN single crystals also produce a TL emission of 2.91 eV caused by recombination of donor–acceptor pairs based on neutral oxygen impurities in the ON nitrogen position and aluminum vacancies (VAl-ON). In the studied submicrocrystals the

SC

formation of such complexes is caused by the high concentration of O and Si impurities. Thus, the results of chemical analysis in the present work and the established deficit in the aluminum

M AN U

sublattice of the studied samples are in good agreement with the above facts and the dominance of the G2 peak (2.87 eV) in the measured CL and TL spectra taking into account ON → (VAl-ON) recombination.

According to papers by Nam et al., 2005; Sedhain et al., 2012; Koppe et al., 2016; Demol et al., 2019, the spectral G1 component (2.04 eV) is formed involving the charge carrier transitions

TE D

between the hole levels of the (VAl-ON) complexes or VAl and the valence band. In turn, the G3 peak agrees well with the emission of 2.4-2.5 eV (480 nm) in structures with a developed surface

EP

and polycrystalline powders (Pastrňák et al., 1974; Nappé et al., 2011; Koppe et al., 2016) and in AlN ceramics with VN defects (Demol et al., 2019). In some cases, it is referred to the transitions

AC C

between the levels of shallow donors and complexes of the (VAl-2ON)-type. As a rule, the formation probability of this defect is less than for (VAl-ON) (Koppe et al., 2016). Consequently, the intensity of ON → (VAl-2ON) radiative transitions should be expectedly lower, which is confirmed by the ratio between G2 and G3 peaks in the present work – IG2/IG3 > 10. Fig. 5 exemplifies the spectral cross sections of the measured 3D dependence, i.e. temperature TL curves. It can be seen that the shape of the latter (shape-factor µg = 0.58-0.60) and the position of the maximum (Tm = 339-343 K) remain almost unchanged in the range of the specified wavelengths. TL peak with a close maximum of Tm = 350 K was observed previously in AlN-Y2O3

ACCEPTED MANUSCRIPT

ceramics after exposure to UV radiation of 243 nm (Trinkler and Berzina, 2014b). It is known that the position and shape of the TL peaks in different structures of aluminum nitride vary significantly depending on the irradiation conditions and stimulation parameters, as well as the type of ionizing radiation used. So, under exposure to γ-rays, thin AlN films exhibit a TL maximum at 480-490 K

RI PT

(Choudhary et al., 2014), and polycrystalline AlN-based samples with various additives (oxygen, yttrium oxide, boron nitride) are characterized by the maximum TL response in the range of 563593 K (Tanaka et al., 1998). After X-ray irradiation of bulk AlN single crystals, TL emission of 360

SC

nm was registered with a temperature peak in the region of 450 K (Soltamov et al., 2011). UV irradiated powders and AlN-Y2O3 ceramics exhibit several TL maxima: 400 K (Nappé et al., 2011)

M AN U

and 470 K (Trinkler and Berzina, 2014b). In this case, the positions of the TL peaks depend noticeably on the mode of the UV irradiation also.

To describe quantitatively the obtained data, we employed the known formalism of the kinetic processes of general order (GOK) (Chen and McKeever, 1997):

−

b b −1

TE D

 s ′′ ( b − 1 ) T  E   EA  I = s ′′n 0 exp  − A   1 + exp − d θ ∫T  k θ   r  kT   o 

s″ – effective frequency factor, s-1; n0 – initial concentration of trapped charge carriers in traps, m-3;

K/s.

EP

EA – trap activation energy, eV; k – Boltzmann constant, eV/K; b – kinetic order; r – heating rate,

AC C

Fig. 5 (solid lines) displays that all the TL curves with a high degree of accuracy (R2 > 0.999) were approximated using a single kinetic component. The parameters obtained for the calculated curves are given in Table 2. The estimate of the activation energy EA (see Table 1) for the thermally stimulated process is in agreement with the results for bulk AlN single crystals (Weinstein et al., 2012), where this parameter characterizes the thermal depth of the nitrogen-vacancy VN-based trap. The calculated value for the order of the kinetics b > 3 allow making a conclusion about a high probability recapture of released charge carriers and the availability of hidden competitive processes

ACCEPTED MANUSCRIPT

between energy defect levels in the band gap, which are actively filled and emptied in the temperature range of the TL peak studied. Thus, it can be concluded that the thermally stimulated recombination processes occurring in the synthesized microcrystalline powder, involve defect complexes of the oxygen–vacancy nature.

RI PT

Defective vacancy levels (VN) in the nitrogen sublattice cause the electron trapping centers to form and, in the case of heating the sample, act as a deep donor. In turn, the recombination (VAl-ON) centers are characterized by a complex structure of ground and excited states. An aluminum

SC

vacancy provides levels of hole capture near the top of the valence band, and impurity oxygen

M AN U

forms excitation levels, the upper of which is located near the bottom of the conduction band.

Conclusion

This paper is devoted to the study of cathodoluminescence and thermally stimulated luminescence processes in the AlN submicrocrystalline powder, which was synthesized by a unique gas phase technique. The grown particles with a size of 0.1- 2.0 µm are crystals as hexagonal prisms

TE D

of regular geometric shape and combinations of a prism with a bipyramid. AlN at hand was deficient in the aluminum sublattice and contained O and Si as main impurities.

EP

It is found the measured CL and TL spectra in the samples have an almost identical form – a single broad peak with a maximum of 420 ± 5 nm. The experimental dependencies obtained are

AC C

approximated within a superposition of three independent spectral components. The 2.87-eV band with a halfwidth of 0.71 eV is shown to play a dominant role in forming the shape of the observed spectra. In addition, the less intense components of 2.04 eV and 2.46 eV are identified in the experimental curves analyzed. It is established that the emission maxima of 2.87 and 2.46 eV can be caused by recombination processes involving electron-hole levels related to impurity oxygen atoms and aluminum vacancies – ON → (VAl-ON) and ON → (VAl-2ON), respectively. Comparing the results of the performed chemical analysis and independent literature data, a conclusion can be

ACCEPTED MANUSCRIPT

made about the hole nature of the emission of 2.04 eV due to transitions between the hole levels of oxygen–vacancy center and the valence band: (VAl-ON) → VB. The TL curves analysis performed within the formalism of the general-order kinetic processes allows one to determine the activation energy EA = 0.58 eV for the thermally stimulated emission

RI PT

observed. The justification of the relationship between the value obtained and the thermal depth of the nitrogen vacancy VN-based active trap is given. Taking calculated values of the kinetics order into account, it can be concluded that the processes of recapture of released charge carriers to the

SC

indicated vacancy levels in the formation mechanisms of the radiation-stimulated response of AlN

M AN U

microcrystals irradiated with electrons have a high probability.

Acknowledgements:

This work was supported partially by Russian Science Foundation (project No. 17-72-10159), Russian Foundation for Basic Research (project No. 18-32-00550) and Act 211 Government of the Russian Federation, contract no. 02.A03.21.0006. I.A.W., Ch.D.V. and A.S.V. thank Minobrnauki

TE D

initiative research project № 16.5186.2017/8.9 for support. S.D.M. thanks scholarship of the President of the Russian Federation to young scientists and postgraduates SP3817.2016.1 for

AC C

EP

financial supporting.

ACCEPTED MANUSCRIPT

References

Afonin, Yu.D., Chaykin, D.V., Kozhevnikova, A.P., Vokhmintsev, A.S., Weinstein, I.A., Shulgin B.V., 2016. Method for producing aluminium nitride whiskers. Russian patent application RU 2617495 C1

RI PT

Bastek, B., Bertram, F., Christen, J., Hempel, T., Dadgar, A., Krost, A., 2009. Analysis of point defects in AlN epilayers by cathodoluminescence spectroscopy. Appl. Phys. Lett. 95, 0321061–0.23106-3. https://doi.org/10.1063/1.3154518

SC

Berzina, B., Trinkler, L., Jakimovica, D., Korsaks, V., Grabis, J., Steins, I., Palcevskis, E., Bellucci, S., Chen, L.-C., Chattopadhyay, S.,Chen, K.-H., 2009. Spectral characterization of

https://doi.org/10.1117/1.3276803

M AN U

bulk and nanostructured aluminum nitride. J.Nanophoton. 3(1), 031950-1 – 031950-16.

Bickermann, M., Epelbaum, B.M., Filip, O., Heimann, P., Nagata, S., Winnacker A., 2009. Point defect content and optical transitions in bulk aluminum nitride crystals. Phys. Status Solidi B 246 (6), 1181–1183. https://doi.org/10.1002/pssb.200880753

TE D

Cao, Y.G., Chen, X.L., Lan, Y.C., Li, J.Y., Xu, Y.P., Xu, T., Liu, Q.L., Liang J.K., 2000. Blue emission and Raman scattering spectrum from AlN nanocrystalline powders. J. Cryst. Growth

EP

213, 198–202. https://doi.org/10.1016/S0022-0248(00)00379-1 Chaykin, D.V., Afonin, Yu.D., Weinstein, I.A., Vokhmintsev, A.S., Shulgin D.B., 2019. Synthesis

AC C

method of aluminium nitride submicron crystals. Russian patent application (submitted). Chen, R., McKeever, S.W.S., 1997. Theory of Thermoluminescence and Related Phenomena. World Scientific, Singapore City. Choudhary, R.K., Soni, A., Mishra, P., Mishra, D.R., Kulkarni, M.S., 2014. Synthesis of aluminum nitride thin films and their potential applications in solid state thermoluminescence dosimeters. J. Lumin. 155, 32–38. https://doi.org/10.1016/j.jlumin.2014.06.016 Demol, G., Paulmier, T., Payan, D., 2019. Cathodoluminescence of aluminum ceramic compounds. J. Appl. Phys. 125, 025110-1 – 025110-9. https://doi.org/10.1063/1.5066434

ACCEPTED MANUSCRIPT

Genji, K., Uchino, T., 2016. Time-resolved photoluminescence characterization of oxygen-related defect centers in AlN. Appl. Phys. Lett. 109, 021113. https://doi.org/10.1063/1.4958891 Jung, H., Xiong, C., Fong, K.Y., Zhang, X., Tang, H.X., 2013. Optical frequency comb generation from

aluminum

nitride

microring

resonator.

Opt.

Lett.

38

(15),

2810–2813.

RI PT

https://doi.org/10.1364/OL.38.002810 Koppe, T., Hofsäss, H., Vetter, U., 2016. Overview of band-edge and defect related luminescence in aluminum nitride. J. Lumin. 178, 267–281. https://doi.org/10.1016/j.jlumin.2016.05.055

SC

Koyama, T., Sugawara, M., Hoshi, T., Urdono, A., Kaeding, J.F., Sharma, R., Nakamura, S., Chichibu, S.F., 2007. Relation between Al vacancies and deep emission bands in AlN

M AN U

epitaxial films grown by NH3-source molecular beam epitaxy. Appl. Phys. Lett. 90, 241914. https://doi.org/10.1063/1.2748315

Liu, J., Zhang, X., Zhang, Y., He, R., Zhu, J., 2001. Novel synthesis of AlN nanowires with controlled

diameters.

J.

Mater.

Res.

16

(11),

3133–3138.

https://doi.org/10.1557/JMR.2001.0432

vacancies

and

TE D

Nam, K.B., Nakarmi, M.L., Lin, J.Y., Jiang, H.X., 2005. Deep impurity transitions involving cation complexes

in

AlGaN

alloys.

Appl.

Phys.

Lett.

86,

222108.

EP

https://doi.org/10.1063/1.1943489

Nappé, J.C., Benabdesselam, M., Grosseau, Ph., Guilhot, D., 2011. Effect of swift heavy ion

AC C

irradiations in polycrystalline aluminum nitride. Nucl. Instrum. Meth. B 269, 100–104. https://doi.org/10.1016/j.nimb.2010.10.025 Pastrňák, J., Pačesová, S., Roskovcová, L., 1974 Luminescent properties of the oxygen impurity centres in AlN. Czech. J. Phys. 24, 1149–1161. Sedhain, A., Lin, J.Y., Jiang, H.X., 2012. Nature of optical transitions involving cation vacancies and

complexes

in

AlN

https://doi.org/10.1063/1.4723693

and

AlGaN.

Appl.

Phys.

Lett.

100,

221107.

ACCEPTED MANUSCRIPT

Shen, L., Wang, N., Xiao, X., 2013. Strong orange luminescence from AlN whiskers. Mater. Lett. 94, 150–153. https://doi.org/10.1016/j.matlet.2012.12.042 Shen, L., Zhang, X., Song, J., Li, F., Qi, D., 2016. White-light emission from AlN dendrites. J. Mater. Sci.-Mater. Electron. 27, 12017–12020. https://doi.org/10.1007/s10854-016-5349-9

RI PT

Solomonov, V.I., Michailov, S.G., Lipchak, A.I., Osipov, V.V., Shpak, V.G., Shunailov, S.A., Yalandin, M.I., Ulmaskulov, M.R., 2006. CLAVI pulsed cathodoluminescence spectroscope. Laser Phys. 16 (1), 126–129. https://doi.org/10.1134/S1054660X06010117

SC

Soltamov, V.A., Ilyin, I.V., Soltamova, A.A., Tolmachev, D.O., Mokhov, E.N., Baranov, P.G., 2011. Identification of the deep-level defects in AlN single crystals: EPR and TL studies.

M AN U

Diam. Relat. Mat. 20, 1085–1089. https://doi.org/ 10.1016/j.diamond.2011.04.009 Spiridonov, D.M., Weinstein, I.A., Vokhmintsev, A.S, Beketov, A.R., 2015. Cathodoluminescence of oxygen-vacancy centers in structures of aluminum nitride. Bull. Russ. Acad. Sci. Phys. 79 (2), 211–214. https://doi.org/10.3103/S106287381502029X

Tanaka, S., Hu, Q., Grishmanov, V., Yoneoka, T., 1998. Thermoluminescence on polycrystalline

TE D

AlN after γ and electron irradiation. Nucl. Instr. and Meth. in Phys. Res. B 141, 547–551. https://doi.org/ 10.1016/S0168-583X(98)00058-5

wavelength

EP

Taniyasu, Y., Kasu, M., Makimoto, T., 2006. An aluminium nitride light-emitting diode with a of

210

nanometres.

Nature

441

(7091),

325–328.

AC C

https://doi.org/10.1038/nature04760 Thapa, S.B., Hertkorn, J., Scholz, F., Prinz, G.M., Leute, R.A.R., Feneberg, M., Thonke, K., Sauer, R., Klein, O., Biskupek, J., Kaiser, U., 2008. Growth and studies of Si-doped AlN layers. J. Cryst. Growth 310, 4939–4941. https://doi.org/10.1016/j.jcrysgro.2008.07.091 Tondare, V.N., Balasubramanian, C., Shende, S.V., Joag, D.S., Godbole, V.P., Bhoraskar S.V., Bhadbhade, M., 2002. Field emission from open ended aluminum nitride nanotubes. Appl. Phys. Lett. 80 (25), 4813–4815. https://doi.org/10.1063/1.1482137

ACCEPTED MANUSCRIPT

Trinkler, L., Berzina, B., Auzina, A., Benabdesselam, M., Iacconi, P., 2007. Use of aluminum nitride for UV radiation dosimetry. Nucl. Instrum. Meth. A 580 (1), 354–357. https://doi.org/10.1016/j.nima.2007.05.177 Trinkler, L., Berzina, B., 2014a. Recombination luminescence in aluminum nitride ceramics.

RI PT

Phys.Stat.Sol. B. 251 (3), 542–548. https://doi.org/10.1002/pssb.201350090 Trinkler, L., Berzina, B., 2014b. Localised transitions in luminescence of AlN ceramics. Radiat. Meas. 71, 232–236. https://doi.org/10.1016/j.radmeas.2014.02.016

crystals

β-irradiation.

under

J.

Lumin.

132,

2109–2113.

M AN U

https://doi.org/10.1016/j.jlumin.2012.03.066

SC

Vokhmintsev, A.S., Weinstein, I.A., Spiridonov, D.M., 2012a. Afterglow in bulk AlN single

Vokhmintsev, A.S., Weinstein, I.A., Spiridonov, D.M., Beketov, D.A., Beketov, A.R., 2012b. Kinetic features of optically stimulated luminescence in aluminum nitride powder. Tech. Phys. Lett. 38 (2), 160–163. https://doi.org/10.1134/S1063785012020319 Vokhmintsev, A., Weinstein, I., Spiridonov, D., 2013. Continuous wave OSL in bulk AlN single

TE D

crystals. Phys. Status Solidi C 10 (3), 457–460. https://doi.org/10.1002/pssc.201200519 Vokhmintsev, A.S., Minin, M.G., Chaykin, D.V., Weinstein, I.A., 2014. A high-temperature

EP

accessory for measurements of the spectral characteristics of thermoluminescence. Instrum. Exp. Tech. 57 (3), 369–373. https://doi.org/10.1134/S0020441214020328

AC C

Vokhmintsev, A.S., Weinstein, I.A., Chaikin, D.V., Fedorov, M.D., Afonin, Yu.D., 2015a. Blue electroluminescence from AlN nanowhiskers. Tech. Phys. Lett. 41 (4), 332–335. https://doi.org/10.1134/S1063785015040161 Vokhmintsev, A.S., Minin, M.G., Henaish, A.M.A., Weinstein, I.A., 2015b. Spectrally resolved thermoluminescence measurements in fluorescence spectrometer. Measurement 66, 90–94. https://doi.org/10.1016/j.measurement.2015.01.012

ACCEPTED MANUSCRIPT

Weinstein, I.A., Vokhmintsev, A.S., Spiridonov, D.M., 2012. Thermoluminescence kinetics of oxygen-related

centers

in

AlN

single

crystals.

Diam.

Relat.

Mat.

25,

59–62.

https://doi.org/10.1016/j.diamond.2012.02.004 Weinstein, I.A., Vokhmintsev, A.S., Chaikin, D.V., Afonin, Yu.D., 2016. Spectral features and

61, 111–114. https://doi.org/10.1016/j.optmat.2016.05.054

RI PT

voltage effects in high-field electroluminescence of AlN filamentary nanocrystals. Opt. Mater.

Zhang, Y., Liu, J., He, R., Zhang, Q., Zhang, X., Zhu, J., 2001. Synthesis of aluminum nitride from

carbon

nanotubes.

Chem.

Mat.

13

(11),

SC

nanowires

https://doi.org/10.1021/cm001422a

3899–3905.

M AN U

Zhao, S., Nguyen, H.P.T., Kibria, M.G., Mi, Z., 2015. III-Nitride nanowire optoelectronics. Prog.

AC C

EP

TE D

Quantum Electron. 44, 14–68. https://doi.org/10.1016/j.pquantelec.2015.11.001

ACCEPTED MANUSCRIPT

Tables

Table 1 – Parameters of CL and TL spectra approximation CL

G1

2.06

0.35

2.04

0.14

G2

2.88

0.75

2.87

0.71

2.46

0.46

G3

–

Table 2 – Shape and kinetic parameters of TL curves Value

Tm, ± 2 K

341

ωT, ± 2 K

71

µg ± 0.01

0.59

EA, ± 0.01 eV 6 -1

0.58 7.9

b, ± 0.1

3.25

EP

> 0.999

AC C

R2

TE D

s″, ± 2.4×10 s

M AN U

Parameter

RI PT

Em, Em, ωE, ωE, ± 0.03 eV ± 0.04 eV ± 0.03 eV ± 0.03 eV

SC

Bands

TL

ACCEPTED MANUSCRIPT

Figure captions

Figure 1. SEM images of grown AlN submicrocrystals. XRD data are shown at the bottom Figure 2. Experimental CL and TL spectra Figure 3. 3D plot for TL spectra measured at different temperatures

RI PT

Figure 4. Examples of CL (D = 7.29 kGy) and TL (T = 337 K) spectra approximations (symbols – experiment, dash lines – Gauss components, solid lines – resulting curves)

Figure 5. TL glow curves at different wavelengths (symbols – experiment, solid lines – GOK

AC C

EP

TE D

M AN U

SC

approximations)

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

Figure 1. SEM images of grown AlN submicrocrystals. XRD data are shown at the bottom

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT

Highlights:

Aluminum nitride submicrocrystals of regular geometric shape have been synthesized Spectral features of cathodo- and thermoluminescence in irradiated AlN have been studied Recombination mechanisms with participating of (VAl-ON)-centers have been discussed

AC C

EP

TE D

M AN U

SC

RI PT

Kinetic parameters of observed thermally stimulated luminescence have been evaluated