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Sefaattin Tongay
Researcher at Arizona State University
Publications - 298
Citations - 26557
Sefaattin Tongay is an academic researcher from Arizona State University. The author has contributed to research in topics: Exciton & van der Waals force. The author has an hindex of 65, co-authored 254 publications receiving 20628 citations. Previous affiliations of Sefaattin Tongay include ICFO – The Institute of Photonic Sciences & Chinese Academy of Sciences.
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Journal ArticleDOI
Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures
Xiaoping Hong,Jonghwan Kim,Su-Fei Shi,Yu Zhang,Chenhao Jin,Yinghui Sun,Sefaattin Tongay,Junqiao Wu,Yanfeng Zhang,Feng Wang +9 more
TL;DR: It is shown that hole transfer from the MoS2 layer to the WS2 layer takes place within 50 fs after optical excitation, a remarkable rate for van der Waals coupled two-dimensional layers, which can enable novel two- dimensional devices for optoelectronics and light harvesting.
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Band offsets and heterostructures of two-dimensional semiconductors
TL;DR: In this paper, the band offsets and heterostructures of monolayer and few-layer transition-metal dichalcogenides MX2 (M = Mo, W; X = S, Se, Te) are investigated from first principles calculations.
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Thermally driven crossover from indirect toward direct bandgap in 2D Semiconductors: MoSe2 versus MoS2
Sefaattin Tongay,Jian Zhou,Can Ataca,Kelvin Lo,Tyler S. Matthews,Jingbo Li,Jeffrey C. Grossman,Junqiao Wu,Junqiao Wu +8 more
TL;DR: It is demonstrated that, in a few-layer sample where the indirect bandgap and direct bandgap are nearly degenerate, the temperature rise can effectively drive the system toward the 2D limit by thermally decoupling neighboring layers via interlayer thermal expansion.
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Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons
Sefaattin Tongay,Joonki Suh,Joonki Suh,Can Ataca,Wen Fan,A. V. Luce,A. V. Luce,Jeong Seuk Kang,Jonathan Liu,Changhyun Ko,Rajamani Raghunathanan,Jian Zhou,Frank Ogletree,Jingbo Li,Jeffrey C. Grossman,Junqiao Wu,Junqiao Wu,Junqiao Wu +17 more
TL;DR: This work investigates effects of anion vacancies in monolayer transition metal dichalcogenides as two-dimensional (2D) semiconductors where the vacancies density is controlled by α-particle irradiation or thermal-annealing and finds a new, sub-bandgap emission peak as well as increase in overall photoluminescence intensity as a result of the vacancy generation.
Journal ArticleDOI
Monolayer behaviour in bulk ReS2 due to electronic and vibrational decoupling
Sefaattin Tongay,Sefaattin Tongay,Hasan Sahin,Changhyun Ko,A. V. Luce,Wen Fan,Wen Fan,Kai Liu,Jian Zhou,Jian Zhou,Ying-Sheng Huang,Ching-Hwa Ho,Jinyuan Yan,D. Frank Ogletree,Shaul Aloni,Jie Ji,Shu-Shen Li,Jingbo Li,François M. Peeters,Junqiao Wu,Junqiao Wu,Junqiao Wu +21 more
TL;DR: A new member of the family ofemiconducting transition metal dichalcogenides, rhenium disulphide (ReS2), where such variation is absent and bulk behaves as electronically and vibrationally decoupled monolayers stacked together.