Interplay between many body effects and Coulomb screening in the optical bandgap of atomically thin MoS2

被引：25

作者：

Park, Youngsin ^{[1
]}

Han, Sang Wook ^{[2
]}

Chan, Christopher C. S. ^{[3
]}

Reid, Benjamin P. L. ^{[3
]}

Taylor, Robert A. ^{[3
]}

Kim, Nammee ^{[4
]}

Jo, Yongcheol ^{[5
]}

Im, Hyunsik ^{[5
]}

Kim, Kwang S. ^{[1
]}

机构：

[1] Ulsan Natl Inst Sci & Technol, Sch Nat Sci, Dept Chem & Phys, Ulsan 44919, South Korea

[2] Univ Ulsan, Dept Phys & Energy, Harvest & Storage Res Ctr, Ulsan 44610, South Korea

[3] Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England

[4] Soongsil Univ, Dept Phys, Seoul 06978, South Korea

[5] Dongguk Univ, Div Phys & Semicond Sci, Seoul 04620, South Korea

来源：

NANOSCALE | 2017年 / 9卷 / 30期

基金：

新加坡国家研究基金会;

关键词：

STRONG PHOTOLUMINESCENCE ENHANCEMENT; GAP RENORMALIZATION; VALLEY POLARIZATION; ELECTRON-ELECTRON; MONOLAYER MOS2; QUANTUM-WELLS; ABSORPTION; EXCITONS; SPECTRA; TRIONS;

D O I：

10.1039/c7nr01834g

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Due to its unique layer-number dependent electronic band structure and strong excitonic features, atomically thin MoS2 is an ideal 2D system where intriguing photoexcited-carrier-induced phenomena can be detected in excitonic luminescence. We perform micro-photoluminescence (PL) measurements and observe that the PL peak redshifts nonlinearly in mono-and bi-layer MoS2 as the excitation power is increased. The excited carrier-induced optical bandgap shrinkage is found to be proportional to n(4/3), where n is the optically-induced free carrier density. The large exponent value of 4/3 is explicitly distinguished from a typical value of 1/3 in various semiconductor quantum well systems. The peculiar n(4/3) dependent optical bandgap redshift may be due to the interplay between bandgap renormalization and reduced exciton binding energy.

引用

页码：10647 / 10652

页数：6

共 42 条

[1]

Cheiwchanchamnangij T., 2011, PHYS REV B, V85

[2] ROOM-TEMPERATURE EXCITONIC NONLINEAR ABSORPTION AND REFRACTION IN GAAS/ALGAAS MULTIPLE QUANTUM WELL STRUCTURES [J].