English  |  正體中文  |  简体中文  |  全文筆數/總筆數 : 57023/90721 (63%)
造訪人次 : 12427680      線上人數 : 63
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library & TKU Library IR team.
搜尋範圍 查詢小技巧:
  • 您可在西文檢索詞彙前後加上"雙引號",以獲取較精準的檢索結果
  • 若欲以作者姓名搜尋,建議至進階搜尋限定作者欄位,可獲得較完整資料
  • 進階搜尋
    請使用永久網址來引用或連結此文件: http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/69630

    題名: Influence of the molecular geometry on the photoexcitations of highly emissive organic semiconductors
    作者: Yang, Shu-chun;Graupner, W.;Guha, S.
    貢獻者: 淡江大學物理學系
    日期: 1999-12
    上傳時間: 2011-10-23 18:46:31 (UTC+8)
    出版者: SPIE-The international society for optical engineering
    摘要: Para-phenylene type molecules are efficient photoluminescence emitters in the ultraviolet-blue-green spectral range. They are used in light emitting diodes (LEDs) and photopumped lasers. Photoexcited para-phenylene type molecules give rise to strong emission from singlet excitons, bleaching of the singlet exciton absorption, induced absorption from triplet excitons and induced absorption from polarons. Since the latter two processes represent absorption of the emitted light of singlet excitons, the presence of polarons and triplet excitons might be a fundamental problem for laser diodes made from para-phenylene type molecules. In our experiments we modify the molecular geometry by the application of hydrostatic pressures up to 80 kbar in a temperature range of 10 to 300 K. In particular we show how triplet and polaron states, which are present in LEDs under operation, react to the induced geometric changes. The spectra of ground state absorption, excited state emission, bleaching of the singlet exciton absorption, induced absorption from triplet excitons and induced absorption from polarons are significantly broadened and shifted in energy. In order to explain the observed behavior we have performed three-dimensional bandstructure calculations within density functional theory for the planar poly(para-phenylene). By varying the intermolecular distances and the length of the polymer repeat unit pressure effects can be simulated.
    關聯: Proceedings of the SPIE v.3797, Organic light-emitting materials and devices III,pp.26-37
    DOI: 10.1117/12.372714
    顯示於類別:[物理學系暨研究所] 會議論文





    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library & TKU Library IR teams. Copyright ©   - 回饋