Amplified spontaneous emission from ZnO in n-ZnO/ZnO nanodots–SiO₂composite/p-AlGaN heterojunction light-emitting diodes

Abstract

This study demonstrates amplified spontaneous emission (ASE) of the ultraviolet (UV) electroluminescence (EL) from ZnO at lambda~380 nm in the n-ZnO/ZnO nanodots-SiO(2) composite/p- Al(0.12)Ga(0.88)N heterojunction light-emitting diode. A SiO(2) layer embedded with ZnO nanodots was prepared on the p-type Al(0.12)Ga(0.88)N using spin-on coating of SiO(2) nanoparticles followed by atomic layer deposition (ALD) of ZnO. An n-type Al-doped ZnO layer was deposited upon the ZnO nanodots-SiO(2) composite layer also by the ALD technique. High-resolution transmission electron microscopy (HRTEM) reveals that the ZnO nanodots embedded in the SiO(2) matrix have diameters of 3-8 nm and the wurtzite crystal structure, which allows the transport of carriers through the thick ZnO nanodots-SiO(2) composite layer. The high quality of the n-ZnO layer was manifested by the well crystallized lattice image in the HRTEM picture and the low-threshold optically pumped stimulated emission. The low refractive index of the ZnO nanodots-SiO(2) composite layer results in the increase in the light extraction efficiency from n-ZnO and the internal optical feedback of UV EL into n-ZnO layer. Consequently, significant enhancement of the UV EL intensity and super-linear increase in the EL intensity, as well as the spectral narrowing, with injection current were observed owing to ASE in the n-ZnO layer.

Zinc Oxide Nanophotonics

“…Important to note, however, that majority of the works in the literature only report on amplified spontaneous emission (ASE), rather than lasing [112,113].…”

Sputtering Power Induced Physical Property Variation of Nickel Oxide Films by Radio Frequency Magnetron Sputtering

“…Especially, the attractiveness of NiO material lies in the fact that the NiO films has an natural p-type conductivity and low preparation costs compared to the high-quality p-type ZnO and GaN materials, which are difficult to achieve due to the less stability and high resistance [5][6][7][8][9][10] . Recently, Patel et al 11 fabricated NiO/ ZnO heterojunction on plastic substrate for ultraviolet photodetector applications.…”

Photonic Crystal Structure of Wing Scales in <I>Sasakia Charonda</I> Butterflies

“…In fact, some investigators have produced replicas of the photonic structures of butterfly scales using atomic layer deposition technique (ALD), 9,10) which is a surface-controlled process of depositing materials with atomic-layer accuracy. 11,12) More structural investigations of the butterfly scales are still required for achieving tunable photonic properties in the artificial scales. The present paper reports on further observations of the wing scales in a male S. charonda butterfly following our previous one, 8) and discusses their microstructures causing the bright iridescence.…”