Enhanced light extraction of GaN-based light-emitting diodes with periodic textured SiO ₂ on Al-doped ZnO transparent conductive layer

Abstract

We report an effective enhancement in light extraction of GaN-based light-emitting diodes (LEDs) with an Al-doped ZnO (AZO) transparent conductive layer by incorporating a top regular textured SiO 2 layer. The 2 inch transparent throughpore anodic aluminum oxide (AAO) membrane was fabricated and used as the etching mask. The periodic pore with a pitch of about 410 nm was successfully transferred to the surface of the SiO 2 layer without any etching damages to the AZO layer and the electrodes. The light output power was enhanced by 19% at 20 mA and 56% at 100 mA compared to that of the planar LEDs without a patterned surface. This approach offers a technique to fabricate a low-cost and large-area regular pattern on the LED chip for achieving enhanced light extraction without an obvious increase of the forward voltage.

Synthesis of Pr-doped ZnO nanoparticles: Their structural, optical, and photocatalytic properties

“…[16] It is widely used in solar cells, sensors, catalysts, luminescence, optoelectronics, biomedical devices, and light-emitting diodes. [17][18][19][20] However, its wide bandgap (3.37 eV) means that it can absorb only UV light (λ < 368.0 nm) that occupies only 3%-5% of the sunlight; this restricts the utilization of the complete solar energy spectrum and leads to low quantum efficiency. [21,22] Besides, the separation of photogenerated electrons from vacancies needs to be strengthened for enhancing the photo-quantum efficiency.…”

High-performance InGaN/GaN MQW LEDs with Al-doped ZnO transparent conductive layers grown by MOCVD using H 2 O as an oxidizer

“…ZnO-based transparent conductive layers (TCLs) have been widely investigated to replace indium tin oxide (ITO) in high-efficiency GaN-based light-emitting diodes (LEDs). [1][2][3][4][5] In our previous work, [6] metal organic chemical vapor deposition (MOCVD) proved to be a good method to grow ZnObased TCLs for GaN-based LEDs application. As reported in literature, [6] the GaN-based LEDs with the MOCVD growing Al-doped ZnO (AZO)-TCL showed an ultra-low forward voltage of 2.86 V (@20 mA) and an epitaxial-like excellent interface between the AZO-TCL and n + -InGaN contact layer.…”