Vacuum processed large area doped thin-film crystals: A new approach for high-performance organic electronics

• Published in: Materials today physics 2021-03, Vol.17, p.100352, Article 100352
• Main Authors: Wang, S.-J., Sawatzki, M., Kleemann, H., Lashkov, I., Wolf, D., Lubk, A., Talnack, F., Mannsfeld, S., Krupskaya, Y., Büchner, B., Leo, K.
• Format: Article
• Language: English
• Subjects: Molecular doping; Organic electronics; Organic field-effect transistor; Organic semiconductors; Organic single crystal; Organic thin-film transistor
• ISSN: 2542-5293; 2542-5293
• DOI: 10.1016/j.mtphys.2021.100352

Rubrene single crystal domains with hundreds of micrometers size fully covering different substrates are achieved by thermal annealing of evaporated amorphous thin films with the help of a thin glassy underlayer. The sufficiently large energy level offset of the underlayer material and rubrene enables high performance staggered bottom gate rubrene crystalline transistors with maximum field-effect linear mobility over 5 cm2V−1s−1 (μAvg = 4.35 ± 0.76 cm2V−1s−1) for short channel devices of 20 μm, comparable to high quality rubrene bulk single crystals. Moreover, since molecular dopants up to several mole percent can be incorporated into the single crystals with a minimal disturbance of the lattice, the contact resistance of the transistors is significantly reduced to around 1 kOhm.cm by contact doping via adlayer epitaxy of p-type doped rubrene. Our results pave the way for novel high-performance organic electronics using crystalline active materials with mass-production compatible deposition techniques. [Display omitted] •Large area doped rubrene thin-film crystals were deposited using vacuum deposition technique.•Doped rubrene thin-film crystals show minimal structural disorder upon doping with molecular dopant.•High performance organic thin-film transistors demonstrated with integration of doped rubrene thin-film crystals.