Nature of Non-emissive Black Spots in Polymer LEDs. Ji-Seon Kim, Peter K. H. Ho, Craig E. Murphy, Nicholas Baynes, and Richard H. Friend Reviewed by Joung-Mo Kang for 6.977, Spring 2002. The Phenomenon Observed The Great Organics Plague. S. H. Kim et al Synthetic Metals 111-112 (2000) 254.
Ji-Seon Kim, Peter K. H. Ho, Craig E. Murphy, Nicholas Baynes, and Richard H. Friend
Reviewed by Joung-Mo Kang for 6.977, Spring 2002
S. H. Kim et al Synthetic Metals 111-112 (2000) 254
McElvain et al. J. Appl. Phys., Vol. 80, No. 10, 15 Nov 1996 6004
Al – 400nm
Ca – 5nm
50:50 F8BT:TFB – 80nm
7% PEDOT in PSSH – 50nm
ITO – substrate
Devices were driven in ambient atmosphere at room temp for 120h with J = 100 mA/cm² and initial brightness L = ~104 cd/m²
Top left figure is an optical picture taken in reflected light. Two ~2 mm
wide pinholes + disks are visible in each of the glass and ITO areas of substrate. Bottom shows same device turned on. The term “black spots” describes this dark patch in the yellow-green EL emission.
Raleigh ScatterRaman Scatter
Raleigh wavelength same as incident,
Raman wavelength is different
DiscussionSo What Does It All Mean?
ComparisonWhere This Paper Fits Into the Current Canon
ComparisonSome Other (Possible) Degradation Defects
CriticismInquiring Minds Want to Know