IOMT

The characteristics of organic light-emitting devices based on aluminum tris-(8-hydroxy-quinoline) (Alq3), N,N'<!--inline-formula content-type="tex">N^'</inline-formula-->-bis(3-methylphenyl)-N,N'<!--inline-formula content-type="tex">N^'</inline-formula-->-diphenylbenzidine (TPD) with novel p-isopropenyl-calix[8]arenestyrene copolymer buffer layer and Al cathode were investigated. The devices with TPD/Alq3/Al were also fabricated in the same way for comparison. The p-isopropenylcalix[8]arenestyrene copolymer used as buffer layer greatly improved the performance of the device and increased the device efficiency and stability.

In this paper we present our results concerning the role of 2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline (bathocuproine, BCP) in OLED structures with emissive layer of Tris-(8-hydroxyquinoline) aluminum (Alq3). It is established that instead of the higher working voltage of devices with bathocuproine their current efficiency significantly increased. This higher efficiency indicates strong hole-blocking nature of bathocuproine (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Organic light-emitting diodes (OLEDs) with improved performances are fabricated using a thin (1 nm) yellow-emitting layer of 5,6,11,12-tetraphenylnaphthacene (Rubrene) inserted at different position in green emitting electroluminescent (EL) layer of bis-(2-(2-hydroxyphenyl) benzothiazole)zinc (Zn(BTz)2) in configuration: ITO/PVK:TPD/ Zn(BTz)2 (x nm)/ Rubrene (1 nm)/ Zn(BTz)2 (75-x nm)/Al, where PVK:TPD is a hole transporting layer of N, N'-bis(3-methylphenyl)-N, N'-diphenylbenzidine (TPD) incorporated in poly(N-vinylcarbazole) (PVK) matrix and Al is a cathode. EL spectra predominantly influenced by Rubrene emission when the doping layer is close to (PVK:TPD)/ Zn(BTz)2 (x→ 0-15 nm) and to Zn(BTz)2/Al (x→ 70-75 nm) interfaces and shift toward emission of Zn(BTz)2 increasing the distance of Rubrene from both interfaces (x→35 nm). The same dependence of the EL efficiency on the position of the doping Rubrene layer in the OLED structure was found.

ABSTRACT Thin film sensors on the basis of evaporated layers of chalcogenide glasses for heavy metal ions are developed. In spite of the promising results and good electrochemical performance, the long-term stability of chalcogenide-based thin film sensors is still a problem. In this paper, AES study was made to clarify the problem with “the aging” of chalcogenide thin film membranes.The electrochemical performance of chalcogenide glass membranes covered with plasma deposited polymer film of polyhexamethyldisiloxane (PHMDSO) and vacuum deposited polyimide (PI) was investigated. It was established that both polymer layers improve the electrochemical characteristics of the membranes—increase the sensitivity, the detection limits and long-term stability while maintaining a stable response time and very good reproducibility.