Substitutional n-type doping of an organic semiconductor investigated by electron paramagnetic resonance spectroscopy

被引:42
作者
Chen, SG
Branz, HM
Eaton, SS
Taylor, PC
Cormier, RA
Gregg, BA
机构
[1] Natl Renewable Energy Lab, Golden, CO 80401 USA
[2] Univ Denver, Dept Chem & Biochem, Denver, CO 80208 USA
[3] Univ Utah, Dept Phys, Salt Lake City, UT 84112 USA
[4] Metropolitan State Coll, Dept Chem, Denver, CO 80204 USA
关键词
D O I
10.1021/jp049628c
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Doping a perylene diimide organic semiconductor with a one-electron reduced perylene diimide containing a covalently bound counterion provides a well-characterized system for understanding doping in organic semiconductors. We obtain insight into the doping process by electron paramagnetic resonance (EPR) measurements of the dopant solutions, the dopant plus host solutions from which thin films are spin-coated, and the resulting solid films. After correction for some trace impurities in the solutions, the spin density incorporated into the solid films is linearly proportional to the added dopant density. Nevertheless, the film conductivity increases superlinearly with dopant concentration. Although neither pure dopant nor host aggregate in solution, they aggregate when combined. This is presumably a result of the delocalization of the dopant electron over a number of host molecules. Angle-dependent EPR measurements on thin films suggest that the g-tensor symmetry axis is close to the pi-pi stacking axis, consistent with relatively delocalized electrons in this crystal direction. Nevertheless, most electrons are not entirely free, but still bound in the vicinity of the dopant cation by Coulomb attraction. At low concentration, dopants appear to segregate primarily to crystallite grain boundaries, while at higher concentration they are incorporated into the bulk of the crystallites. About half of the spins are paired in the solid at room temperature, and more at lower temperature.
引用
收藏
页码:17329 / 17336
页数:8
相关论文
共 38 条
  • [1] UNUSUAL BAND-FILLING AND COUNTERION ORDERING EFFECTS IN A PHTHALOCYANINE MOLECULAR-METAL - SINGLE-CRYSTAL STUDIES OF NI(PC)(CLO4)Y
    ALMEIDA, M
    KANATZIDIS, MG
    TONGE, LM
    MARKS, TJ
    MARCY, HO
    MCCARTHY, WJ
    KANNEWURF, CR
    [J]. SOLID STATE COMMUNICATIONS, 1987, 63 (06) : 457 - 461
  • [2] BARD AJ, 1980, ELECTROCHEMICAL METH
  • [3] Charge transport in poly(p-phenylene vinylene) light-emitting diodes
    Blom, PWM
    Vissenberg, MCJM
    [J]. MATERIALS SCIENCE & ENGINEERING R-REPORTS, 2000, 27 (3-4) : 53 - 94
  • [4] Polymer-perylene diimide heterojunction solar cells
    Breeze, AJ
    Salomon, A
    Ginley, DS
    Gregg, BA
    Tillmann, H
    Hörhold, HH
    [J]. APPLIED PHYSICS LETTERS, 2002, 81 (16) : 3085 - 3087
  • [5] Self-organization in thin films of liquid crystalline perylene diimides
    Cormier, RA
    Gregg, BA
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 1997, 101 (51): : 11004 - 11006
  • [6] Synthesis and characterization of liquid crystalline perylene diimides
    Cormier, RA
    Gregg, BA
    [J]. CHEMISTRY OF MATERIALS, 1998, 10 (05) : 1309 - 1319
  • [7] ELECTRICAL PROPERTIES OF N-TYPE GERMANIUM
    DEBYE, PP
    CONWELL, EM
    [J]. PHYSICAL REVIEW, 1954, 93 (04): : 693 - 706
  • [8] STABLE-SOLUTIONS OF DOPED THIOPHENE OLIGOMERS
    DELEEUW, DM
    [J]. SYNTHETIC METALS, 1993, 57 (01) : 3597 - 3602
  • [9] Dye sensitization of nanocrystalline tin oxide by perylene derivatives
    Ferrere, S
    Zaban, A
    Gregg, BA
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 1997, 101 (23): : 4490 - 4493
  • [10] Large increases in photocurrents and solar conversion efficiencies by UV illumination of dye sensitized solar cells
    Ferrere, S
    Gregg, BA
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 2001, 105 (32): : 7602 - 7605