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

Abstract

The fabrication and operation of a monolithic InGaN alternating-current light-emitting diode ͑LED͒ 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 V rms lighting applications.

A Comparative Study of GaN‐Based Direct Current and Alternating Current High Voltage Light‐Emitting Diodes

“…One approach is to alleviate the efficiency droop by increasing the chip size of LEDs, leading to poor current spreading performance . Another approach is to divide a large area LED chip into numerous serially connected LED cells, that is direct current high‐voltage LEDs (DC‐HV LEDs) and alternating current high‐voltage LEDs (AC‐HV LEDs) . Because HV LEDs are operated at high voltage and low driving current, fewer power transformers from a regular voltage source are required.…”

Laser Micromachining for Gallium Nitride Based Light-Emitting Diodes

“…In the proposed approach, a laser beam turning mirror was introduced to the optical path to achieve a continuously-tunable range of tilting angles for beam projection, while retaining the beam quality. Laser micromachining is a potential simple, inexpensive and highthroughput alternative method for creating geometrically-shaped GaN LEDs compared to other available technologies [6,7,8]. K.N.…”

Thermal analyses of alternating current light-emitting diodes

“…[http://dx.doi.org/10.1063/ 1.4823806] Alternating current InGaN/GaN light-emitting diodes [1][2][3] (AC-LEDs) can be operated in AC power without rectifiers and regulators which are otherwise needed in DC power. So far, most studies have focused on issues of circuit designs and hardware fabrications.…”