Separating positive and negative magnetoresistance in organic semiconductor devices

被引：190

作者：

Bloom, F. L. ^{[1
,2
]}

Wagemans, W. ^{[1
,2
]}

Kemerink, M. ^{[1
,2
]}

Koopmans, B. ^{[1
,2
]}

机构：

[1] Eindhoven Univ Technol, COBRA Res Inst, NL-5600 MB Eindhoven, Netherlands

[2] Eindhoven Univ Technol, Ctr NanoMat, Dept Appl Phys, NL-5600 MB Eindhoven, Netherlands

来源：

PHYSICAL REVIEW LETTERS | 2007年 / 99卷 / 25期

关键词：

D O I：

10.1103/PhysRevLett.99.257201

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We study the transition between positive and negative organic magnetoresistance (OMAR) in tris-(8 hydroxyquinoline) aluminium (Alq(3)), in order to identify the elementary mechanisms governing this phenomenon. We show how the sign of OMAR changes as function of the applied voltage and temperature. The transition from negative to positive magnetoresistance (MR) is found to be accompanied by an increase in slope of log(I) versus log(V). ac admittance measurements show this transition coincides with the onset of minority charge (hole) injection in the device. All these observations are consistent with two simultaneous contributions with opposite sign of MR, which may be assigned to holes and electrons having different magnetic field responses.

引用

收藏

页数：4

相关论文

共 14 条

[1] Electron and hole transport in poly(p-phenylene vinylene) devices [J].

Blom, PWM ;

deJong, MJM ;

Vleggaar, JJM .

APPLIED PHYSICS LETTERS, 1996, 68 (23) :3308-3310

[2] Bipolaron mechanism for organic magnetoresistance [J].

Bobbert, P. A. ;

Nguyen, T. D. ;

van Oost, F. W. A. ;

Koopmans, B. ;

Wohlgenannt, M. .

PHYSICAL REVIEW LETTERS, 2007, 99 (21)

[3] Magnetoresistance and efficiency measurements of Alq3-based OLEDs [J].

Desai, Pratik ;

Shakya, P. ;

Kreouzis, T. ;

Gillin, W. P. ;

Morley, N. A. ;

Gibbs, M. R. J. .

PHYSICAL REVIEW B, 2007, 75 (09)

[4] Large magnetoresistance at room temperature in semiconducting polymer sandwich devices -: art. no. 185 [J].

Francis, TL ;

Mermer, Ö ;

Veeraraghavan, G ;

Wohlgenannt, M .

NEW JOURNAL OF PHYSICS, 2004, 6 :1-8

[5] Negative capacitances in low-mobility solids [J].

Gommans, HHP ;

Kemerink, M ;

Janssen, RAJ .

PHYSICAL REVIEW B, 2005, 72 (23)

[6] Transport and recombination in organic light-emitting diodes studied by electrically detected magnetic resonance [J].

Graeff, CFO ;

Silva, GB ;

Nüesch, F ;

Zuppiroli, L .

EUROPEAN PHYSICAL JOURNAL E, 2005, 18 (01) :21-28

[7] CALCULATION OF FREQUENCY-DEPENDENCE OF ADMITTANCE OF SCLC DIODES [J].

KASSING, R .

PHYSICA STATUS SOLIDI A-APPLIED RESEARCH, 1975, 28 (01) :107-117

[8] Large magnetoresistance in nonmagnetic π-conjugated semiconductor thin film devices -: art. no. 205202 [J].

Mermer, O ;

Veeraraghavan, G ;

Francis, TL ;

Sheng, Y ;

Nguyen, DT ;

Wohlgenannt, M ;

Köhler, A ;

Al-Suti, MK ;

Khan, MS .

PHYSICAL REVIEW B, 2005, 72 (20)

[9] 2-CARRIER SPACE-CHARGE-LIMITED CURRENT IN A TRAP-FREE INSULATOR [J].

PARMENTER, RH ;

RUPPEL, W .

JOURNAL OF APPLIED PHYSICS, 1959, 30 (10) :1548-1558

[10] Anomalous room temperature magnetoresistance in organic semiconductors [J].

Prigodin, V. N. ;

Bergeson, J. D. ;

Lincoln, D. M. ;

Epstein, A. J. .

SYNTHETIC METALS, 2006, 156 (9-10) :757-761