Roles of binding energy and diffusion length of singlet and triplet excitons in organic heterojunction solar cells

Monishka Narayan, Jai Singh

    Research output: Contribution to journalArticle

    Abstract

    The influence of binding energy and diffusion length on the dissociation of excitons in organic solids is studied. The binding energy and excitonic Bohr radius of singlet and triplet excitons are calculated and compared using the dissociation energy of 0.3 eV, which is provided by the lowest unoccupied molecular orbital offset in heterojunction organic solar cells. A relation between the diffusion coefficient and diffusion length of singlet and triplet excitons is derived using the Förster and Dexter transfer processes and are plotted as a function of the donor-acceptor separation. The diffusion length reduces nearly to a zero if the distance between donor and acceptor is increased to more than 1.5 nm. It is found that the donor-acceptor separation needs to be ≤ 1.5 nm for easy dissociation on singlet excitons leading to better conversion efficiency in heterojunction organic solar cells. 
    Original languageEnglish
    Pages (from-to)2386-2389
    Number of pages4
    JournalPhysica Status Solidi (C) Current Topics in Solid State Physics
    Volume9
    Issue number12
    DOIs
    Publication statusPublished - Dec 2012

    Fingerprint Dive into the research topics of 'Roles of binding energy and diffusion length of singlet and triplet excitons in organic heterojunction solar cells'. Together they form a unique fingerprint.

  • Cite this