Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons

被引：948

作者：

Tongay, Sefaattin ^{[1
,2
]}

Suh, Joonki ^{[1
,2
]}

Ataca, Can ^{[3
]}

Fan, Wen ^{[1
]}

Luce, Alexander ^{[1
,4
]}

Kang, Jeong Seuk ^{[1
]}

Liu, Jonathan ^{[1
]}

Ko, Changhyun ^{[1
]}

Raghunathanan, Rajamani ^{[3
]}

Zhou, Jian ^{[1
]}

Ogletree, Frank ^{[4
]}

Li, Jingbo ^{[2
]}

Grossman, Jeffrey C. ^{[3
]}

Wu, Junqiao ^{[1
,2
,4
]}

机构：

[1] Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA

[2] Chinese Acad Sci, Inst Semicond, Beijing 100083, Peoples R China

[3] MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA

[4] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA

来源：

SCIENTIFIC REPORTS | 2013年 / 3卷

关键词：

MONOLAYER;

D O I：

10.1038/srep02657

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Point defects in semiconductors can trap free charge carriers and localize excitons. The interaction between these defects and charge carriers becomes stronger at reduced dimensionalities, and is expected to greatly influence physical properties of the hosting material. We investigated effects of anion vacancies in monolayer transition metal dichalcogenides as two-dimensional (2D) semiconductors where the vacancies density is controlled by alpha-particle irradiation or thermal-annealing. We found a new, sub-bandgap emission peak as well as increase in overall photoluminescence intensity as a result of the vacancy generation. Interestingly, these effects are absent when measured in vacuum. We conclude that in opposite to conventional wisdom, optical quality at room temperature cannot be used as criteria to assess crystal quality of the 2D semiconductors. Our results not only shed light on defect and exciton physics of 2D semiconductors, but also offer a new route toward tailoring optical properties of 2D semiconductors by defect engineering.

引用

页数：5

共 24 条

[1] Visibility of dichalcogenide nanolayers [J].

Benameur, M. M. ;

Radisavljevic, B. ;

Heron, J. S. ;

Sahoo, S. ;

Berger, H. ;

Kis, A. .

NANOTECHNOLOGY, 2011, 22 (12)

[2] IMPROVED TETRAHEDRON METHOD FOR BRILLOUIN-ZONE INTEGRATIONS [J].

BLOCHL, PE ;

JEPSEN, O ;

ANDERSEN, OK .

PHYSICAL REVIEW B, 1994, 49 (23) :16223-16233

[3] OPTICAL SPECTROSCOPY OF A 2-DIMENSIONAL ELECTRON-GAS NEAR THE METAL-INSULATOR-TRANSITION [J].

FINKELSTEIN, G ;

SHTRIKMAN, H ;

BARJOSEPH, I .

PHYSICAL REVIEW LETTERS, 1995, 74 (06) :976-979

[4] Semiempirical GGA-type density functional constructed with a long-range dispersion correction [J].

Grimme, Stefan .

JOURNAL OF COMPUTATIONAL CHEMISTRY, 2006, 27 (15) :1787-1799

[5] Phonon softening and direct to indirect band gap crossover in strained single-layer MoSe2 [J].

Horzum, S. ;

Sahin, H. ;

Cahangirov, S. ;

Cudazzo, P. ;

Rubio, A. ;

Serin, T. ;

Peeters, F. M. .

PHYSICAL REVIEW B, 2013, 87 (12)

[6] Atomic-scale structures and electronic states of defects on Ar+-ion irradiated MoS2 [J].

Inoue, Akihiro ;

Komori, Takahiro ;

Shudo, Ken-ichi .

JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA, 2013, 189 :11-18

[7] Anomalous Lattice Vibrations of Single- and Few-Layer MoS2 [J].

Lee, Changgu ;

Yan, Hugen ;

Brus, Louis E. ;

Heinz, Tony F. ;

Hone, James ;

Ryu, Sunmin .

ACS NANO, 2010, 4 (05) :2695-2700

[8] Growth of Large-Area and Highly Crystalline MoS2 Thin Layers on Insulating Substrates [J].

Liu, Keng-Ku ;

Zhang, Wenjing ;

Lee, Yi-Hsien ;

Lin, Yu-Chuan ;

Chang, Mu-Tung ;

Su, ChingYuan ;

Chang, Chia-Seng ;

Li, Hai ;

Shi, Yumeng ;

Zhang, Hua ;

Lai, Chao-Sung ;

Li, Lain-Jong .

NANO LETTERS, 2012, 12 (03) :1538-1544

[9]

Mak KF, 2013, NAT MATER, V12, P207, DOI [10.1038/nmat3505, 10.1038/NMAT3505]

[10] Electronic Structure of Few-Layer Graphene: Experimental Demonstration of Strong Dependence on Stacking Sequence [J].

Mak, Kin Fai ;

Shan, Jie ;

Heinz, Tony F. .

PHYSICAL REVIEW LETTERS, 2010, 104 (17)

← 1 2 3 →