2007/04/30 by C. Krellner, S. Haas, C. Goldmann +5
Engineering · Materials Science · Physics and Astronomy · #Conducting polymers and applications #Organic Electronics and Photovoltaics #Organic Light-Emitting Diodes Research #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.75.245115
published as Phys. Rev. B 75, 245115 (2007) · published in Phys. Rev. B, high quality figures: http://www.cpfs.mpg.de/~krellner/
openalex publication_date 2007/06/18 · arxiv created 2007/06/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The density of trap states in the band gap of semiconducting organic single crystals has been measured quantitatively and with high energy resolution by means of the experimental method of temperature-dependent space-charge-limited-current spectroscopy. This spectroscopy has been applied to study bulk rubrene single crystals, which are shown by this technique to be of high chemical and structural quality. A density of deep trap states as low as \ensuremath∼1015\phantom\rule0.3em0excm^\ensuremath-3 is measured in the purest crystals, and the exponentially varying shallow trap density near the band edge could be identified (one decade in the density of states per \ensuremath∼25\phantom\rule0.3em0exmeV). Furthermore, we have induced and spectroscopically identified an oxygen-related sharp hole bulk trap state at 0.27\phantom\rule0.3em0exeV above the valence band.