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SUMMARY Organic photodetectors based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) blends with indium tin oxide (ITO) modified by phosphonic acid-based self-assembled monolayer (SAM) treatment in a short time are investigated. The mixed SAMs serve to tune the surface free energy and the work function of ITO by varying the blend ratio. The phosphonic acid-based SAM treatment results not only in lowering of the injection barrier at the ITO/organic layer interface but also in the lowering of the contact resistance between ITO and the organic layer, as shown by impedance spectroscopy in P3HT hole-only device with SAMs. P3HT:PCBM device with ITO modified by short treatment time of 1H,1H,2H,2H-perfluorooctane-phosphonic acid exhibits an incident-photon-to-current conversion efficiency of above 50% at -2 V, a high on/off ratio, and improved durability. [ABSTRACT FROM AUTHOR]

Poly(methyl methacrylate) (PMMA) gate dielectric formed using fluorine‐based solvent, CF3CH2OCF2CHF2 (AGC, AE‐3000), is useful to prevent mixing of the dielectric layer with the emissive layer for top‐gated organic light‐emitting transistor (OLET) device fabrication. The device performance of OLETs based on a poly(p‐phenylene vinylene) derivative, Super Yellow, is improved because of the fabrication without intermixing. For an OLET with Pt‐tetraphenyltetrabenzoporphyrin [Pt(tpbp)] doped in poly(alkylfluorene), a near‐infrared emission from Pt(tpbp) and a relatively high external quantum efficiency of approximately 1% are achieved. This device fabrication method opens perspectives in the development of the damage‐free fabrication processes in printed top‐gated OLETs. [ABSTRACT FROM AUTHOR]