Patent ID: 9373554
Filing Date: 2016-06-21
CPC Classification: H01L

Claim Text:
1. A method of monitoring an OLED production process for making an OLED device, the OLED device having a layered structure comprising an anode layer and a cathode layer, said anode and cathode layers sandwiching a hole injection layer, a hole transport layer and at least one organic light emitting layer, the method of monitoring comprising: fabricating at least one reference OLED device similar to said OLED device, wherein said at least one reference OLED device has a layered structure corresponding to said OLED device and a range of hole injection and/or transport layer thicknesses; characterizing a spectral variation of a light output of said at least one reference OLED device with respect to variation in said hole injection and/or transport layer thickness, wherein said characterization of said spectral variation of said light output comprises determining a set of tristimulus values for said light output; partially fabricating a said OLED device, wherein said partial fabrication comprises depositing one or more layers comprising at least said hole injection and/or transport layer; measuring a thickness of said one or more layers comprising at least said hole injection and/or transport layer; predicting a light output for said partially fabricated OLED device, in a target color space, from said measuring, using said characterized spectral variation; converting either said spectral characterization or said predicted light output from said tristimulus values, to said target color space; and adjusting said thickness of said one or more layers comprising at least said hole injection and/or transport layer to adapt said light output to a target light output in said target color space.