Enriched Zn82Se is a very promising material for the detection of the neutrionoless double beta decay. The 82Se isotope acts as the source of the decay, and ZnSe detects the scintillation and bolometric events. Due to the high cost in the preparation of the Zn82Se material, the optimization of its properties, especially those related to the scintillation process, is mandatory. It is well known that excellent scintillation efficiency in ZnSe is obtained when the material presents close donor–acceptor pairs, as, for example, the A-centers. In this work, neutron irradiation was used to study formation of point defects in enriched and non-enriched ZnSe samples. Applying instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectroscopy, the enrichment of Zn82Se samples was determined to ∼95%, in addition, trace impurities such as Cu, I, and Na were quantified by INAA at the μg/g level. Based on electron paramagnetic resonance (EPR) and photo-EPR measurements, we show that irradiation with fast neutrons induced point defects such as the isolated zinc vacancy (VZn) and a new low-symmetric donor center called NC1, which we tentatively assign to Zn di-interstitials. Low-temperature photoluminescence measurements of the neutron-irradiated Zn82Se revealed three broad PL bands centered in the visible spectral range. Based on the INAA analysis shown in this work, we attribute the previously unidentified 540 nm PL band in the Zn82Se sample to recombination between shallow donors and deep copper acceptors. The formation of point defects by neutron irradiation and their stability are discussed.

1.
D. C.
Harris
,
Materials for Infrared Windows and Domes: Properties and Performance
(
SPIE
,
1999
).
2.
S.
Guha
,
J. M.
DePuydt
,
M. A.
Haase
,
J.
Qiu
, and
H.
Cheng
, “
Degradation of II–VI based blue-green light emitters
,”
Appl. Phys. Lett.
63
(
23
),
3107
3109
(
1993
).
3.
J. D.
Vergados
,
H.
Ejiri
, and
F.
Šimkovic
, “
Theory of neutrinoless double-beta decay
,”
Rep. Prog. Phys.
75
(
10
),
106301
(
2012
).
4.
L.
Cardani
, “Neutrinoless double beta decay overview,” (arXiv:1810.12828 (
2018
), pp.
24
28
.
5.
C.
Arnaboldi
,
C.
Brofferio
,
O.
Cremonesi
,
L.
Gironi
,
M.
Pavan
,
G.
Pessina
, and
E.
Previtali
, “
A novel technique of particle identification with bolometric detectors
,”
Astropart. Phys.
34
(
11
),
797
804
(
2011
).
6.
I.
Dafinei
,
M.
Fasoli
,
F.
Ferroni
,
E.
Mihokova
,
F.
Orio
,
S.
Pirro
, and
A.
Vedda
, “
Low temperature scintillation in ZnSe crystals
,”
IEEE Trans. Nucl. Sci.
57
(
3
),
1470
1474
(
2010
).
7.
S.
Nagorny
,
L.
Cardani
,
N.
Casali
,
I.
Dafinei
,
L.
Pagnanini
,
L.
Pattavina
, and
K.
Schaeffner
, “
Quenching factor for alpha particles in ZnSe scintillating bolometers
,”
IOP Conf. Ser.: Mater. Sci. Eng.
169
,
012011
(
2017
).
8.
B. C.
Silva
,
R.
de Oliveira
,
G. M.
Ribeiro
,
L. A.
Cury
,
A. S.
Leal
,
S.
Nagorny
, and
K.
Krambrock
, “
Characterization of high-purity 82 Se-enriched ZnSe for double-beta decay bolometer/scintillation detectors
,”
J. Appl. Phys.
123
(
8
),
085704
(
2018
).
9.
G. D.
Watkins
, “
EPR observation of close Frenkel pairs in irradiated ZnSe
,”
Phys. Rev. Lett.
33
(
4
),
223
225
(
1974
).
10.
G. D.
Watkins
, “
Intrinsic defects in II–VI semiconductors
,”
J. Cryst. Growth
159
(
1–4
),
338
344
(
1996
).
11.
F. C.
Rong
,
W. A.
Barry
,
J. F.
Donegan
, and
G. D.
Watkins
, “
Vacancies, interstitials, and close Frenkel pairs on the zinc sublattice of ZnSe
,”
Phys. Rev. B
54
(
11
),
7779
7788
(
1996
).
12.
K.
Chow
and
G.
Watkins
, “
The electronic structure of interstitial zinc in its two Td sites in ZnSe
,”
Phys. B
273–274
,
861
865
(
1999
).
13.
K.
Chow
and
G.
Watkins
, “
Optically induced migration of interstitial zinc in ZnSe: Caught in the act
,”
Phys. Rev. Lett.
81
(
10
),
2084
2087
(
1998
).
14.
G. D.
Watkins
and
K. H.
Chow
, “
Self-interstitials in semiconductors: What we are learning from interstitial Zn in ZnSe
,”
Phys. B
273–274
,
7
14
(
1999
).
15.
K. H.
Chow
and
G. D.
Watkins
, “
Electronic structure and migrational properties of interstitial zinc in ZnSe
,”
Phys. Rev. B
60
(
12
),
8628
8639
(
1999
).
16.
F.
Rong
and
G. D.
Watkins
, “
Observation by optically detected magnetic resonance of Frenkel pairs in irradiated ZnSe
,”
Phys. Rev. Lett.
56
(
21
),
2310
2313
(
1986
).
17.
N.
Wang
,
F. C.
Wellstood
,
B.
Sadoulet
,
E. E.
Haller
, and
J.
Beeman
, “
Electrical and thermal properties of neutron-transmutation-doped Ge at 20 mK
,”
Phys. Rev. B
41
(
6
),
3761
3768
(
1990
).
18.
E. D.
Wheeler
,
J. L.
Boone
,
J. W.
Farmer
, and
H. R.
Chandrasekhar
, “
Neutron transmutation doping as an experimental probe for As in ZnSe
,”
Phys. Rev. B
53
(
23
),
15617
15621
(
1996
).
19.
E. D.
Wheeler
,
J. L.
Boone
,
J. W.
Farmer
, and
H. R.
Chandrasekhar
, “
Neutron transmutation doping as an experimental probe for Cu Zn in ZnSe
,”
J. Appl. Phys.
81
(
1
),
524
526
(
1997
).
20.
J. L.
Patel
,
J. J.
Davies
, and
J. E.
Nicholls
, “
Direct optically detected magnetic resonance observation of a copper centre associated with the green emission in ZnSe
,”
J. Phys., C: Solid State Phys.
14
(
35
),
5545
5557
(
1981
).
21.
M.
Godlewski
,
W. E.
Lamb
, and
B. C.
Cavenett
, “
ODMR investigations of recombination processes in ZnSe:Cu
,”
Solid State Commun.
39
(
4
),
595
599
(
1981
).
22.
M. Â. B. C.
Menezes
and
R.
Jaćimović
, “
Optimised k0-instrumental neutron activation method using the TRIGA Mark I IPR-R1 reactor at CDTN/CNEN, Belo Horizonte, Brazil
,”
Nucl. Instrum. Methods Phys. Res., Sect. A
564
(
2
),
707
715
(
2006
).
23.
R.
Jaćimović
,
B.
Smodiš
,
T.
Bučar
, and
P.
Stegnar
, “
k0-NAA quality assessment by analysis of different certified reference materials using the KAYZERO/SOLCOI software
,”
J. Radioanal. Nucl. Chem.
257
(
3
),
659
663
(
2003
).
24.
M.
Saiki
,
M. C.
da Silva
,
R.
Fulfaro
, and
M. B. A.
Vasconcellos
, “
Study on instrumental neutron activation analysis of aluminium in geological and biological reference materials
,”
J. Trace Microprobe Tech.
20
(
4
),
517
525
(
2002
).
25.
F.
De Corte
, “
The k0-standardization method : A move to the optimization of neutron activation analysis
,”
Habilitation thesis
(
University of Ghent
,
1987
).
26.
A. S.
Leal
,
M. A. B. C.
Menezes
,
I.
Dalmazio
,
F. P.
Sepe
,
T. C. B.
Gomes
,
A. S.
Santana
,
L. H.
Cunha
, and
R.
Jacimovic
,
Latest Research into Quality Control
, 1st ed. (
Zagreb Intech
,
2013
), Vol. 1, pp.
227
241
.
27.
I.
Dafinei
,
S.
Nagorny
,
S.
Pirro
,
L.
Cardani
,
M.
Clemenza
,
F.
Ferroni
, and
M.
Enculescu
, “
Production of 82Se enriched zinc selenide (ZnSe) crystals for the study of neutrinoless double beta decay
,”
J. Cryst. Growth
475
(
1
),
158
170
(
2017
).
28.
K.
Irmscher
and
M.
Prokesch
, “
Spectroscopic evidence and control of compensating native defects in doped ZnSe
,”
Mater. Sci. Eng. B
80
(
1–3
),
168
172
(
2001
).
29.
G. N.
Ivanova
,
D. D.
Nedeoglo
,
N. D.
Negeoglo
,
V. P.
Sirkeli
,
I. M.
Tiginyanu
, and
V. V.
Ursaki
, “
Interaction of intrinsic defects with impurities in Al doped ZnSe single crystals
,”
J. Appl. Phys.
101
(
6
),
063543
(
2007
).
30.
Comissão Nacional de Energia Nuclear, see http://appasp.cnen.gov.br/seguranca/normas/pdf/pr301_11.pdf for “CNEN-NN-3.01—Diretrizes Básicas de Proteção Radiológica, Posição Regulatória-3.01/001:2011” (last accessed March 19, 2020).
31.
NIST, see https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl for “Atomic Weights and Isotopic Composition for All Elements” (last accessed July 9, 2020).
33.
ENDF, see “Database Version of 2020-07-07, Library JEFF-3.3” (last accessed July 20, 2020), available at https://www-nds.iaea.org/exfor/endf.htm.
34.
See https://www.nndc.bnl.gov/nudat2/ for “NuDat 2.8” (last accessed May 6, 2020).
35.
F. S.
Ham
, “
Jahn-Teller effects in electron paramagnetic resonance spectra
,” in
Electron Paramagnetic Resonance
(
Plenum Publishing Corp.
,
New York
,
1969
).
36.
R. S.
Title
, “
Paramagnetic-resonance spectra of the 3d5 configuration of chromium in ZnSe and ZnTe
,”
Phys. Rev.
133
(
6A
),
A1613
A1616
(
1964
).
37.
M.
Prokesch
,
K.
Irmscher
,
J.
Gebauer
, and
R.
Krause-Rehberg
, “
Reversible conductivity control and quantitative identification of compensating defects in ZnSe bulk crystals
,”
J. Cryst. Growth
214–215
,
988
992
(
2000
).
38.
J.-M.
Spaeth
,
J. R.
Niklas
, and
R. H.
Bartram
,
Structural Analysis of Point Defects in Solids
(Springer-Verlag, Berlin, Heidelberg,
1992
).
39.
K. M.
Lee
,
L. S.
Dang
, and
G. D.
Watkins
, “
Optically detected magnetic resonance of the zinc vacancy in ZnSe
,”
Solid State Commun.
35
(
7
),
527
530
(
1980
).
40.
P. M.
Mooney
and
S. T.
Pantelides
,
Deep Centres in Semiconductors: Gordon and Breach Science Publishers
, 2nd ed. (
Gordon and Breach Science Publishers
,
1992
), pp.
643
665
.
41.
D. V.
Lang
and
S. T.
Pantelides
,
Deep Centres in Semiconductors: Gordon and Breach Science Publishers
, 2nd ed. (
Gordon and Breach Science Publishers
,
1992
), pp.
591
641
.
42.
R.
de Oliveira
,
S.
Balabanov
, and
K.
Krambrock
, “
Establishment of the conditions to improve the luminescence properties of ZnSe for application as scintillating bolometer in the search for neutrinoless double beta decay
,”
J. Lumin.
233
,
117930
(
2021
).
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