Highly Efficient Organic Light-Emitting Devices for General Illumination (Phase II)

Investigating Organization
Physical Optics Corporation

Principal Investigator(s)
Paul Shnitser

Subcontractor
None

Funding Source
Small Business Innovation R&D, Phase II

Award
DOE Share: $749,987

Contract Period
8/8/07 - 8/7/09

Only a small portion of the photons generated within an OLED are emitted from the device.  To overcome this problem with a novel and efficient lighting system, Physical Optics Corporation (POC) proposed in Phase I to develop a new High-Efficiency OLED (HE-OLED) system, forming their holographic Light Shaping Diffuser on a new OLED substrate structure.  This structure can be fabricated on both large glass substrates and flexible polymer rolls.  It improves external efficiency by significantly reducing total internal reflection at the OLED/substrate interface, and by significantly reducing the probability of photons leaking through the waveguide mode on this interface.  This substrate includes two transparent polymer layers-one with a high refractive index matching that of the ITO electrode, and one with a low refractive index, n. A Teflon AF (fluorinated-(ethylenic-cyclo oxyaliphatic ethylenic substituted) copolymer) layer about 5 micrometers thick with a low refractive index (n approximately 1.3), is deposited on a conventional soda-lime glass base or flexible polymer base.  The high-n polymer layer between the surface relief structure and the OLED anode makes it possible to deposit the ITO layer on a flat surface, ensuring the low electrical resistivity of the ITO layer and minimizing ohmic losses in this layer.

Developing OLED substrates with suitable encapsulated light scattering structures and the technology for their mass production at low cost are the goals of the proposed Phase II project.

Content dated 2/08