Patent ID: 9184410
Filing Date: 2015-11-10
Classification: H01L

Abstract:
1. A method of making an integrated barrier and optical enhancement stack for protecting and improving the light out coupling of encapsulated white OLEDs comprising; providing a co-doped white OLED having a transparent electrode; selecting a plasma protective layer having a refractive index in a range of about 1.1 to about 1.9, the plasma protective layer adjacent to the transparent electrode of the white OLED; optimizing a thickness of the plasma protective layer for the white OLED within a range of about 20 nm to about 50 nm; selecting an initial inorganic barrier layer having a refractive index in a range of about 1.55 to about 2, the initial inorganic barrier layer adjacent to the transparent electrode in the white OLED; optimizing a thickness of the initial inorganic barrier layer for the white OLED within a range of about 40 nm to about 240 nm; selecting a barrier stack comprising at least a pair of inorganic barrier layers and a polymeric decoupling layer between the inorganic barrier layers, the inorganic barrier layer having a refractive index in a range of about 1.55 to about 2, and the polymeric decoupling layer having a refractive index in a range of about 1.4 to about 1.65, the barrier stack adjacent to the initial inorganic barrier layer; optimizing a thickness of the inorganic barrier layer within a range of about 20 nm to about 80 nm and the polymeric decoupling layer of the barrier stack within in a range of about 0.2 μm to about 4 μm, wherein the thickness of at least one of the plasma protective layer, initial inorganic barrier layer, the inorganic barrier layer, or the polymeric decoupling layer are optimized for at least one of total efficiency, or intentional color point shift so that the encapsulated white OLED has enhanced light outcoupling compared to a bare white OLED; depositing the plasma protective layer having the optimized thickness adjacent to the transparent electrode of the white OLED; depositing the initial inorganic barrier layer having the optimized thickness adjacent to the plasma protective layer; and depositing the barrier stack having the optimized thickness for the inorganic barrier layer and the polymeric decoupling layer adjacent to the initial inorganic barrier layer, wherein the initial inorganic barrier layer is different from the inorganic barrier layer of the barrier stack and further wherein the improving the light out coupling of the encapsulated OLED is achieved without either (a) a scattering layer placed adjacent the OLED, initial inorganic barrier layer or barrier stack or (b) a quarter-wave stack placed adjacent the OLED, initial inorganic barrier layer or barrier stack.