Interconnected alternating-current light-emitting diode arrays isolated by laser micromachining

– GY Mak, EY Lam, and HW Choi

Microphotograph showing layout of the ac-LED, with circuit diagram superimposed. The directions of current flow during the positive and negative cycles of a sinusoidal voltage are shown with the red arrow (marked as “+ve”) and the blue arrow (marked as “–ve”), respectively. The overall dimensions of the device array are 1.38 × 1.38 mm².

Journal of Vacuum Science & Technology B, vol. 29, 1, pp. 011025 (2011)

The fabrication and operation of a monolithic InGaN alternating-current light-emitting diode (LED) based on the bridge rectifier design are demonstrated. The device consists of on-chip interconnected LED elements that have been isolated by direct-write laser micromachining, a powerful tool well-suited for rapid device prototyping. The effects of capacitors coupled to the dc path of the rectifier have been investigated. Although an increase of radiant flux can be achieved through capacitive voltage smoothening, the wall-plug efficiency drops as a result. The device can be applied to 12 Vrms lighting applications.

DOI: 10.1116/1.3533949