Increased Responsivity of Suspended Graphene Photodetectors

被引：169

作者：

Freitag, Marcus ^{[1
]}

Low, Tony ^{[1
]}

Avouris, Phaedon ^{[1
]}

机构：

[1] IBM Corp, TJ Watson Res Ctr, Yorktown Hts, NY 10598 USA

来源：

NANO LETTERS | 2013年 / 13卷 / 04期

关键词：

Graphene; photodetector; p-n junction; hot electron; surface polar phonon; electron cooling; PHOTOCURRENT; PHOTORESPONSE; DISSIPATION;

D O I：

10.1021/nl4001037

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The responsivity of graphene photodetectors depends critically on the elevated temperature of the electronic subsystem upon photoexcitation. We investigate the role of the substrate in providing cooling pathways for photoexcited carriers under ambient conditions by partially suspending few-layer graphene over a trench. Through photocurrent microscopy, we observe p-n junctions near the supported/suspended interfaces that produce photothermoelectric currents. Most importantly, we find the photocurrent in suspended p-n junctions to be an order of magnitude larger than in supported structures. This enhancement is attributed to the elimination of a dominant electronic cooling channel via the surface phonons of the polar substrate. Our work documents this mechanism of energy exchange between graphene and its environment, and it points to the importance of dielectric engineering for future improved graphene photodetectors.

引用

页码：1644 / 1648

页数：5

共 32 条

[1]

[Anonymous], APPL PHYS LETT

[2] Supercollision cooling in undoped graphene [J].

Betz, A. C. ;

Jhang, S. H. ;

Pallecchi, E. ;

Ferreira, R. ;

Feve, G. ;

Berroir, J-M. ;

Placais, B. .

NATURE PHYSICS, 2013, 9 (02) :109-112

[3] Hot Electron Cooling by Acoustic Phonons in Graphene [J].

Betz, A. C. ;

Vialla, F. ;

Brunel, D. ;

Voisin, C. ;

Picher, M. ;

Cavanna, A. ;

Madouri, A. ;

Feve, G. ;

Berroir, J. -M. ;

Placais, B. ;

Pallecchi, E. .

PHYSICAL REVIEW LETTERS, 2012, 109 (05)

[4] Electronic Cooling in Graphene [J].

Bistritzer, R. ;

MacDonald, A. H. .

PHYSICAL REVIEW LETTERS, 2009, 102 (20)

[5]

Chen SS, 2012, NAT MATER, V11, P203, DOI [10.1038/NMAT3207, 10.1038/nmat3207]

[6]

Craciun MF, 2009, NAT NANOTECHNOL, V4, P383, DOI [10.1038/NNANO.2009.89, 10.1038/nnano.2009.89]

[7] OBSERVATION OF ANDERSON LOCALIZATION IN AN ELECTRON GAS [J].

CUTLER, M ;

MOTT, NF .

PHYSICAL REVIEW, 1969, 181 (03) :1336-&

[8] Controlling Electron-Phonon Interactions in Graphene at Ultrahigh Carrier Densities [J].

Efetov, Dmitri K. ;

Kim, Philip .

PHYSICAL REVIEW LETTERS, 2010, 105 (25)

[9]

Freitag M, 2013, NAT PHOTONICS, V7, P53, DOI [10.1038/NPHOTON.2012.314, 10.1038/nphoton.2012.314]

[10] Energy Dissipation in Graphene Field-Effect Transistors [J].

Freitag, Marcus ;

Steiner, Mathias ;

Martin, Yves ;

Perebeinos, Vasili ;

Chen, Zhihong ;

Tsang, James C. ;

Avouris, Phaedon .

NANO LETTERS, 2009, 9 (05) :1883-1888

← 1 2 3 4 →