TY  - JOUR
AU  - Tian, Jianjun
AU  - Ivanovski, Valentin N.
AU  - Abeykoon, Milinda
AU  - Martin, Rodica M.
AU  - Baranets, Sviatoslav
AU  - Martin, Catalin
AU  - Liu, Yu
AU  - Du, Qianheng
AU  - Wang, Aifeng
AU  - Chen, Shuzhang
AU  - Tong, Xiao
AU  - Zhang, Weifeng
AU  - Bobev, Svilen
AU  - Koteski, Vasil J.
AU  - Petrović, Čedomir
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10108
AB  - Transition metal dichalcogenides attract considerable attention due to a variety of interesting properties, including long-range magnetism in nanocrystals. Here we investigate the magnetic, thermal, and electrical properties of an FeTe2 single crystal with iron vacancy defects. Magnetic measurements show a paramagnetic state and the absence of magnetic order with low anisotropy in the magnetic susceptibility. Fe 3d orbitals are well hybridized, contributing to the bad metal electrical resistivity. Observed thermal conductivity values below room temperature are rather low and comparable to those of high-performance thermoelectric materials. Our results indicate that FeTe2 can form in a highly defective marcasite crystal structure which can be exploited in future materials design.
T2  - Physical Review B
T1  - Absence of long-range magnetic order in Fe1−δ Te2  (δ ≈ 0.1) crystals
VL  - 104
IS  - 22
SP  - 224109
DO  - 10.1103/PhysRevB.104.224109
ER  - 

@article{
author = "Tian, Jianjun and Ivanovski, Valentin N. and Abeykoon, Milinda and Martin, Rodica M. and Baranets, Sviatoslav and Martin, Catalin and Liu, Yu and Du, Qianheng and Wang, Aifeng and Chen, Shuzhang and Tong, Xiao and Zhang, Weifeng and Bobev, Svilen and Koteski, Vasil J. and Petrović, Čedomir",
year = "2021",
abstract = "Transition metal dichalcogenides attract considerable attention due to a variety of interesting properties, including long-range magnetism in nanocrystals. Here we investigate the magnetic, thermal, and electrical properties of an FeTe2 single crystal with iron vacancy defects. Magnetic measurements show a paramagnetic state and the absence of magnetic order with low anisotropy in the magnetic susceptibility. Fe 3d orbitals are well hybridized, contributing to the bad metal electrical resistivity. Observed thermal conductivity values below room temperature are rather low and comparable to those of high-performance thermoelectric materials. Our results indicate that FeTe2 can form in a highly defective marcasite crystal structure which can be exploited in future materials design.",
journal = "Physical Review B",
title = "Absence of long-range magnetic order in Fe1−δ Te2  (δ ≈ 0.1) crystals",
volume = "104",
number = "22",
pages = "224109",
doi = "10.1103/PhysRevB.104.224109"
}

Tian, J., Ivanovski, V. N., Abeykoon, M., Martin, R. M., Baranets, S., Martin, C., Liu, Y., Du, Q., Wang, A., Chen, S., Tong, X., Zhang, W., Bobev, S., Koteski, V. J.,& Petrović, Č.. (2021). Absence of long-range magnetic order in Fe1−δ Te2  (δ ≈ 0.1) crystals. in Physical Review B, 104(22), 224109.
https://doi.org/10.1103/PhysRevB.104.224109

Tian J, Ivanovski VN, Abeykoon M, Martin RM, Baranets S, Martin C, Liu Y, Du Q, Wang A, Chen S, Tong X, Zhang W, Bobev S, Koteski VJ, Petrović Č. Absence of long-range magnetic order in Fe1−δ Te2  (δ ≈ 0.1) crystals. in Physical Review B. 2021;104(22):224109.
doi:10.1103/PhysRevB.104.224109 .

Tian, Jianjun, Ivanovski, Valentin N., Abeykoon, Milinda, Martin, Rodica M., Baranets, Sviatoslav, Martin, Catalin, Liu, Yu, Du, Qianheng, Wang, Aifeng, Chen, Shuzhang, Tong, Xiao, Zhang, Weifeng, Bobev, Svilen, Koteski, Vasil J., Petrović, Čedomir, "Absence of long-range magnetic order in Fe1−δ Te2  (δ ≈ 0.1) crystals" in Physical Review B, 104, no. 22 (2021):224109,
https://doi.org/10.1103/PhysRevB.104.224109 . .

TY  - JOUR
AU  - Tian, Jianjun
AU  - Ivanovski, Valentin N.
AU  - Szalda, David
AU  - Lei, Hechang
AU  - Wang, Aifeng
AU  - Liu, Yu
AU  - Zhang, Weifeng
AU  - Koteski, Vasil J.
AU  - Petrović, Čedomir
PY  - 2019
UR  - http://pubs.acs.org/doi/10.1021/acs.inorgchem.8b03089
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8082
AB  - We report the synthesis and characterization of Fe 0.36(4) Pd 0.64(4) Se 2 with a pyrite-type structure. Fe 0.36(4) Pd 0.64(4) Se 2 was synthesized using ambient pressure flux crystal growth methods even though the space group Pa3 is high-pressure polymorph for both FeSe 2 and PdSe 2 . Combined experimental and theoretical analysis reveal magnetic spin glass state below 23 K in 1000 Oe that stems from random Fe/Pd occupancies on the same atomic site. The frozen-in magnetic randomness contributes significantly to electronic transport. Electronic structure calculations confirm dominant d-electron character of hybridized bands and large density of states near the Fermi level. Flux-grown single crystal alloys in Pd-Fe-Se atomic system therefore open new pathway for exploring different polymorphs in crystal structures and their novel properties. © 2019 American Chemical Society.
T2  - Inorganic Chemistry
T1  - Fe0.36(4)Pd 0.64(4)Se 2 : Magnetic Spin-Glass Polymorph of FeSe2 and PdSe2 Stable at Ambient Pressure
VL  - 58
IS  - 5
SP  - 3107
EP  - 3114
DO  - 10.1021/acs.inorgchem.8b03089
ER  - 

@article{
author = "Tian, Jianjun and Ivanovski, Valentin N. and Szalda, David and Lei, Hechang and Wang, Aifeng and Liu, Yu and Zhang, Weifeng and Koteski, Vasil J. and Petrović, Čedomir",
year = "2019",
abstract = "We report the synthesis and characterization of Fe 0.36(4) Pd 0.64(4) Se 2 with a pyrite-type structure. Fe 0.36(4) Pd 0.64(4) Se 2 was synthesized using ambient pressure flux crystal growth methods even though the space group Pa3 is high-pressure polymorph for both FeSe 2 and PdSe 2 . Combined experimental and theoretical analysis reveal magnetic spin glass state below 23 K in 1000 Oe that stems from random Fe/Pd occupancies on the same atomic site. The frozen-in magnetic randomness contributes significantly to electronic transport. Electronic structure calculations confirm dominant d-electron character of hybridized bands and large density of states near the Fermi level. Flux-grown single crystal alloys in Pd-Fe-Se atomic system therefore open new pathway for exploring different polymorphs in crystal structures and their novel properties. © 2019 American Chemical Society.",
journal = "Inorganic Chemistry",
title = "Fe0.36(4)Pd 0.64(4)Se 2 : Magnetic Spin-Glass Polymorph of FeSe2 and PdSe2 Stable at Ambient Pressure",
volume = "58",
number = "5",
pages = "3107-3114",
doi = "10.1021/acs.inorgchem.8b03089"
}

Tian, J., Ivanovski, V. N., Szalda, D., Lei, H., Wang, A., Liu, Y., Zhang, W., Koteski, V. J.,& Petrović, Č.. (2019). Fe0.36(4)Pd 0.64(4)Se 2 : Magnetic Spin-Glass Polymorph of FeSe2 and PdSe2 Stable at Ambient Pressure. in Inorganic Chemistry, 58(5), 3107-3114.
https://doi.org/10.1021/acs.inorgchem.8b03089

Tian J, Ivanovski VN, Szalda D, Lei H, Wang A, Liu Y, Zhang W, Koteski VJ, Petrović Č. Fe0.36(4)Pd 0.64(4)Se 2 : Magnetic Spin-Glass Polymorph of FeSe2 and PdSe2 Stable at Ambient Pressure. in Inorganic Chemistry. 2019;58(5):3107-3114.
doi:10.1021/acs.inorgchem.8b03089 .

Tian, Jianjun, Ivanovski, Valentin N., Szalda, David, Lei, Hechang, Wang, Aifeng, Liu, Yu, Zhang, Weifeng, Koteski, Vasil J., Petrović, Čedomir, "Fe0.36(4)Pd 0.64(4)Se 2 : Magnetic Spin-Glass Polymorph of FeSe2 and PdSe2 Stable at Ambient Pressure" in Inorganic Chemistry, 58, no. 5 (2019):3107-3114,
https://doi.org/10.1021/acs.inorgchem.8b03089 . .

TY  - JOUR
AU  - Subair, Riyas
AU  - Di Girolamo, Diego
AU  - Bodik, Michal
AU  - Nadazdy, Vojtech
AU  - Li, Bo
AU  - Nadazdy, Peter
AU  - Marković, Zoran M.
AU  - Benkovicova, Monika
AU  - Chlpik, Juraj
AU  - Kotlar, Mario
AU  - Halahovets, Yuriy
AU  - Šiffalovič, Peter
AU  - Jergel, Matej
AU  - Tian, Jianjun
AU  - Brunetti, Francesca
AU  - Majkova, Eva
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8435
AB  - The doping effect of carbon nanodots (CNDs) in the PC61BM electron-transport layer on the performance of inverted planar MAPbI3 perovskite solar cells (PSCs) having two different kinds of the hole-transport layer, namely organic PEDOT:PSS and inorganic NiOx, was investigated. The CH3NH3PbI3 perovskite layer was deposited in air at 35% humidity. An average 11% and 12% enhancement of the power conversion efficiency (PCE) was achieved for 1 wt% CNDs doping in the PSCs with PEDOT:PSS and NiOx, respectively. This improvement is attributed to high electron density of CNDs resulting in a triple increase of the electrical conductivity of the PC61BM layer and passivation of the perovskite/PC61BM interface that is reflected by an increase of the open-circuit voltage. In line with this, parallel resistance and fill factor of the PSCs are also improved. Moreover, the energy-resolved electrochemical impedance spectroscopy revealed additional free-charge carriers in the PC61BM layer generated under illumination that were detected via the polaron states formation in the band gap with positive effect on the short-circuit current. All these factors contribute to the PCE improvement. Stability tests of the PSC with PEDOT:PSS under a continuous 24 hour 1.5 AM illumination showed a five times smaller final PCE decrease for the 1 wt% CNDs doping of the PC61BM layer comparing to the undoped counterpart. The passivation effect of CNDs, namely electron filling the traps formed by the photo-dimerization and photo-oxidation of PC61BM molecules, is responsible for this remarkable improvement of the short-term stability. © 2019 International Solar Energy Society
T2  - Solar Energy
T1  - Effect of the doping of PC61BM electron transport layer with carbon nanodots on the performance of inverted planar MAPbI3 perovskite solar cells
VL  - 189
SP  - 426
EP  - 434
DO  - 10.1016/j.solener.2019.07.088
ER  - 

@article{
author = "Subair, Riyas and Di Girolamo, Diego and Bodik, Michal and Nadazdy, Vojtech and Li, Bo and Nadazdy, Peter and Marković, Zoran M. and Benkovicova, Monika and Chlpik, Juraj and Kotlar, Mario and Halahovets, Yuriy and Šiffalovič, Peter and Jergel, Matej and Tian, Jianjun and Brunetti, Francesca and Majkova, Eva",
year = "2019",
abstract = "The doping effect of carbon nanodots (CNDs) in the PC61BM electron-transport layer on the performance of inverted planar MAPbI3 perovskite solar cells (PSCs) having two different kinds of the hole-transport layer, namely organic PEDOT:PSS and inorganic NiOx, was investigated. The CH3NH3PbI3 perovskite layer was deposited in air at 35% humidity. An average 11% and 12% enhancement of the power conversion efficiency (PCE) was achieved for 1 wt% CNDs doping in the PSCs with PEDOT:PSS and NiOx, respectively. This improvement is attributed to high electron density of CNDs resulting in a triple increase of the electrical conductivity of the PC61BM layer and passivation of the perovskite/PC61BM interface that is reflected by an increase of the open-circuit voltage. In line with this, parallel resistance and fill factor of the PSCs are also improved. Moreover, the energy-resolved electrochemical impedance spectroscopy revealed additional free-charge carriers in the PC61BM layer generated under illumination that were detected via the polaron states formation in the band gap with positive effect on the short-circuit current. All these factors contribute to the PCE improvement. Stability tests of the PSC with PEDOT:PSS under a continuous 24 hour 1.5 AM illumination showed a five times smaller final PCE decrease for the 1 wt% CNDs doping of the PC61BM layer comparing to the undoped counterpart. The passivation effect of CNDs, namely electron filling the traps formed by the photo-dimerization and photo-oxidation of PC61BM molecules, is responsible for this remarkable improvement of the short-term stability. © 2019 International Solar Energy Society",
journal = "Solar Energy",
title = "Effect of the doping of PC61BM electron transport layer with carbon nanodots on the performance of inverted planar MAPbI3 perovskite solar cells",
volume = "189",
pages = "426-434",
doi = "10.1016/j.solener.2019.07.088"
}

Subair, R., Di Girolamo, D., Bodik, M., Nadazdy, V., Li, B., Nadazdy, P., Marković, Z. M., Benkovicova, M., Chlpik, J., Kotlar, M., Halahovets, Y., Šiffalovič, P., Jergel, M., Tian, J., Brunetti, F.,& Majkova, E.. (2019). Effect of the doping of PC61BM electron transport layer with carbon nanodots on the performance of inverted planar MAPbI3 perovskite solar cells. in Solar Energy, 189, 426-434.
https://doi.org/10.1016/j.solener.2019.07.088

Subair R, Di Girolamo D, Bodik M, Nadazdy V, Li B, Nadazdy P, Marković ZM, Benkovicova M, Chlpik J, Kotlar M, Halahovets Y, Šiffalovič P, Jergel M, Tian J, Brunetti F, Majkova E. Effect of the doping of PC61BM electron transport layer with carbon nanodots on the performance of inverted planar MAPbI3 perovskite solar cells. in Solar Energy. 2019;189:426-434.
doi:10.1016/j.solener.2019.07.088 .

Subair, Riyas, Di Girolamo, Diego, Bodik, Michal, Nadazdy, Vojtech, Li, Bo, Nadazdy, Peter, Marković, Zoran M., Benkovicova, Monika, Chlpik, Juraj, Kotlar, Mario, Halahovets, Yuriy, Šiffalovič, Peter, Jergel, Matej, Tian, Jianjun, Brunetti, Francesca, Majkova, Eva, "Effect of the doping of PC61BM electron transport layer with carbon nanodots on the performance of inverted planar MAPbI3 perovskite solar cells" in Solar Energy, 189 (2019):426-434,
https://doi.org/10.1016/j.solener.2019.07.088 . .

TY  - JOUR
AU  - Wang, Aifeng
AU  - Wu, Lijun
AU  - Ivanovski, Valentin N.
AU  - Warren, J. B.
AU  - Tian, Jianjun
AU  - Zhu, Yimei
AU  - Petrović, Čedomir
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1232
AB  - We report critical current density (J(c)) in tetragonal FeS single crystals, similar to iron-based superconductors with much higher superconducting critical temperatures (T-c). The Jc is enhanced three times by 6% Se doping. We observe scaling of the normalized vortex pinning force as a function of reduced field at all temperatures. Vortex pinning in FeS and FeS0.94Se0.06 shows contribution of core-normal surfacelike pinning. Reduced temperature dependence of J(c) indicates that dominant interaction of vortex cores and pinning centers is via scattering of charge carriers with reduced mean free path (delta l), in contrast to KxFe2-ySe2 where spatial variations in T-c (delta T-c) prevails.
T2  - Physical Review B: Condensed Matter and Materials Physics
T1  - Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06)
VL  - 94
IS  - 9
DO  - 10.1103/PhysRevB.94.094506
ER  - 

@article{
author = "Wang, Aifeng and Wu, Lijun and Ivanovski, Valentin N. and Warren, J. B. and Tian, Jianjun and Zhu, Yimei and Petrović, Čedomir",
year = "2016",
abstract = "We report critical current density (J(c)) in tetragonal FeS single crystals, similar to iron-based superconductors with much higher superconducting critical temperatures (T-c). The Jc is enhanced three times by 6% Se doping. We observe scaling of the normalized vortex pinning force as a function of reduced field at all temperatures. Vortex pinning in FeS and FeS0.94Se0.06 shows contribution of core-normal surfacelike pinning. Reduced temperature dependence of J(c) indicates that dominant interaction of vortex cores and pinning centers is via scattering of charge carriers with reduced mean free path (delta l), in contrast to KxFe2-ySe2 where spatial variations in T-c (delta T-c) prevails.",
journal = "Physical Review B: Condensed Matter and Materials Physics",
title = "Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06)",
volume = "94",
number = "9",
doi = "10.1103/PhysRevB.94.094506"
}

Wang, A., Wu, L., Ivanovski, V. N., Warren, J. B., Tian, J., Zhu, Y.,& Petrović, Č.. (2016). Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06). in Physical Review B: Condensed Matter and Materials Physics, 94(9).
https://doi.org/10.1103/PhysRevB.94.094506

Wang A, Wu L, Ivanovski VN, Warren JB, Tian J, Zhu Y, Petrović Č. Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06). in Physical Review B: Condensed Matter and Materials Physics. 2016;94(9).
doi:10.1103/PhysRevB.94.094506 .

Wang, Aifeng, Wu, Lijun, Ivanovski, Valentin N., Warren, J. B., Tian, Jianjun, Zhu, Yimei, Petrović, Čedomir, "Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06)" in Physical Review B: Condensed Matter and Materials Physics, 94, no. 9 (2016),
https://doi.org/10.1103/PhysRevB.94.094506 . .