New dual-curvature microlens array with high fill-factor for organic light emitting diode modules

A new method to fabricate a novel dual-curvature microlens array with high fill-factor using the proximity printing in lithography process is reported. The lens profiles including dual-curvatures which are a new shape composed of triangle and hexagon. We utilized the UV proximity printing by controlling a printing gap between the mask and substrate. The designed a high density microlens array pattern can be fabricated dual-curvature microlens array with high fill-factor in photoresist. It is due to the UV light diffraction to deflect away from the aperture edges and produces a certain exposure in photoresist material outside the aperture edges. A dual-curvature microlens array with 0.48 of height ratio can boost axial luminance up to 22%. Therefore, dual-curvature microlens array will be an economical solution for increasing the luminance of organic light emitting diodes.