Maskless Surface Patterning of AlGaInP Light-Emitting Diodes by Photochemical Laser Interference Etching

Laser nanofabrication has attracted great interest for mass production of microstructures with desired or improved properties. We report here a facile, maskless method for fabricating two-dimensional (2D) quasiperiodic patterns on AlGaInP light-emitting diodes (LEDs) by photochemical laser interference etching. The interference pattern produced by two 532 nm laser beams is transferred to the top GaP window layer of the AlGaInP LEDs by photochemical etching of GaP in an etchant composed hydrofluoric acid (HF) and hydrogen peroxide (H2O2). The etched GaP surface contains 2D quasiperiodic pyramidal structures with a period of 150 ± 10 nm, which can dramatically increase the light extraction efficiency of the AlGaInP LEDs by 70%. This maskless patterning method is general and can be applied to fabricating patterns on optoelectronic devices based on other semiconductor materials.