Abstract
ABSTRACTThe enhancement of the luminance of organic light-emitting diode (OLED) panels with various areas (2.25–6084 mm2) using a microlens array (MLA) film was investigated. The luminance enhancement was dependent on the viewing angle, and the largest enhancement (64%) was observed in the normal direction while 60 and 18% enhancements were observed at 60 and 30°, which led to lower enhancement (38%) of the total luminous flux compared with the luminance enhancement (64%) in the normal direction. The luminance enhancement with the MLA film also depended on the panel area, and the smaller panels showed lower luminance enhancement than the larger ones. As for the small panels, the straying light beyond the panel areas significantly affected the luminance of the panels, and over 60% luminance enhancement was observed in the normal direction for the large panels (2500 and 6084 mm2) with the MLA film while only 48 and 58% luminance enhancements were observed at the small panels (2.25 and 70 mm2).
Highlights
Organic light-emitting diode (OLED) technologies have matured for lighting application
An externally attached microlens array (MLA) can be understood as having the function of eliminating or reducing the spectral dependence of the OLED panel on the viewing angle
The enhancements at the 60 and 30° viewing angles were 60 and 18%, respectively. These results indicate that the MLA film mainly directs the light towards the normal direction
Summary
Organic light-emitting diode (OLED) technologies have matured for lighting application. OLED lighting can offer high luminous efficiency, color tunability, flexibility, transparency, low thickness, large luminescence area, etc. In OLED lighting applications, a large illumination area is favored. In the internal extraction techniques, the light extraction component is formed between the substrate (e.g. glass) and the transparent electrode (e.g. indium tin oxide, ITO). In the external extraction techniques, the light extraction component is positioned at the exterior surface of the glass [4,5]. The external light extraction technology using microlens array (MLA) films was focused on [6,7,8,9]. The area and viewing angle effects on the light extraction using MLA were investigated. The area dependence of the MLA in OLED was addressed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
