[6p-A203-1~19] 12.4 Organic light-emitting devices and organic transistors

△ [6p-A203-10] Reduced phosphomolybdic acid hole injection materials for solution-processed organic light-emitting devices toward room temperature processing

〇Kohei Endo¹, Satoru Ohisa^1,2,3, Kosuke Kasuga¹, Yong-Jin Pu^1,2,3, Takayuki Chiba^1,2,3, Junji Kido^1,2,3 (1.Grad. Schl. of Org. Mater. Sci., Yamagata Univ., 2.ROEL, Yamagata Univ., 3.FROM, Yamagata Univ.)

Keywords:solution-processable molybdenum oxides, room temperature process, organic light-emitting devices

In a solution-processed phosphomolybdic acid (PMA) hole injection layer (HIL), it is known that high temperature thermal baking of PMA after film formation is essential to achieve efficient hole injection characteristics. However, this high temperature treatment is not suitable for fabrication of a flexible device using a resin substrate. In this work, we developed an efficient HIL comprising a pre-reduced PMA (red-PMA) for room temperature processing. The red-PMA solution exhibited a blue color, and the UV-vis-NIR absorption spectrum of the film showed absorption bands derived from reduction of Mo (VI). Organic light-emitting devices using the red-PMA HIL showed low driving voltage without baking processes after film formation.