公开(公告)号：US20170150573A1

公开(公告)日：2017-05-25

申请号：US15322371

申请日：2015-06-19

Applicant: Cambridge Display Technology Limited

Inventor： Natasha M.J. Conway ,  Colin Baker ,  Philip Benzie ,  Alexander Doust ,  Niall MacCarthy

IPC: H05B33/08 ,  H01L51/52 ,  H01L27/32 ,  H01L51/50

CPC classification number: H01L51/5212 ,  H01L27/3244 ,  H01L51/5088 ,  H01L51/5209 ,  H01L2251/5361 ,  H01L2251/562 ,  H01L2251/564 ,  H05B33/0896 ,  Y02B20/36

Abstract: A method of increasing the lifetime of an ITO-free organic lighting system comprises: providing an organic lighting element having a substrate (12) bearing a set of anode electrode metal tracks (14), a conductive organic layer (16) over said metal tracks, an organic light emitting layer (18) over said conductive organic layer, and a cathode electrode layer (20) over said organic light emitting layer, wherein said metal comprises copper, and wherein said conductive organic layer comprises a doped conducting polymer, and driving the organic lighting element with a pulsed current drive. A biphasic pulse is employed having a first, on-phase with a defined current drive and a second, off-phase with a drive having a defined potential difference of zero volts across the lighting element. The anode electrode metal may have a higher work function than the cathode electrode layer. During said zero level drive portion the different work functions provide a reverse bias electric field within the organic lighting element.