Letter of Clarification Udc/Gpec Research And License Arrangements

EXHIBIT 10.23 June 4, 2004 VIA OVERNIGHT MAIL Mr. John F. Ritter
Office of Technology and Trademark Licensing
Princeton University
4 New South Building
P.O. Box 36
Princeton, NJ 08544 Re: Clarification of UDC/GPEC Research and License Arrangements Dear John,Under the 2002 Amended Research Agreement between Universal Display Corporation (" UDC" ) and Princeton University, and by extension the subcontract between Princeton University and the University of Southern California (" USC" ), no other commercial entity can fund Dr. Stephen R. Forrest' s or Dr. Mark E. Thompson' s work in the area of thin film organic electronics for displays, lasers, lighting, organic tft' s, organic memories and other thin-film organic devices, but not including thin film organic photovoltaic cells for solar energy conversion. Similarly, under the new 2004 Research Agreement between Global Photonic Energy Corporation (" GPEC" ) and Princeton University, and by extension the subcontract between Princeton University and USC, no other commercial entity can fund Dr. Forrest' s or Dr. Thompson' s work in the area of organic photovoltaic cells for solar energy conversion.It is agreed that an " organic photovoltaic cell for solar energy conversion," also known as a photovoltaic (" PV" ) device or solar cell, is a type of photosensitive optoelectronic device that is specifically used to generate electrical power. The attached definitions are to be used for further clarification of the differences between PV devices and other classes of photosensitive optoelectronic devices. As a general rule, a photovoltaic cell provides power to a circuit, device or equipment, but does not provide a signal or current to control detection circuitry, or the output of information from the detection circuitry. In contrast, a photodetector or photoconductor provides a signal or current to control detection circuitry, or the output of information from the detection circuitry but does not provide power to the circuitry, device or equipment.Based on the foregoing and in order to eliminate any confusion moving forward, it is agreed that all intellectual property developed following the date hereof based on work conducted by Dr. Forrest and/or Dr. Thompson or their research teams under the UDC 2002 Amended Research Agreement and/or the new GPEC 2004 Research Agreement will be exclusively licensed to UDC under the UDC License Agreement with Princeton ...