Enhanced excitonic emission efficiency in porous GaN

Abstract

We investigate the optical properties of porous GaN films of different porosities, focusing on the behaviors of the excitonic features in time-integrated and time-resolved photoluminescence. A substantial enhancement of both excitonic emission intensity and recombination rate, along with insignificant intensity weakening under temperature rise, is observed in the porous GaN films. These observations are in line with (i) the local concentration of electric field at GaN nanoparticles and pores due to the depolarization effect, (ii) the efficient light extraction from the nanoparticles. Besides, the porosification enlarges the surface of the air/semiconductor interface, which further promotes the extraction efficiency and suppresses non-radiative recombination channels. Our findings open a way to increasing the emission efficiency of nanophotonic devices based on porous GaN.

Tetrabutylammonium (TBA)-Doped Methylammonium Lead Iodide: High Quality and Stable Perovskite Thin Films

“…This emission is three times higher than undoped MAPbI 3 thin film. The results could be attributed to reducing trap density states with decreased charge recombination, which improved the thin film's optoelectronic properties (Brennan et al, 2017;Ngo et al, 2018).…”

Assessment of the Enhancement for the Excitation Emission in Porous Gan using Photoluminescence

“…The quality and the existence of defects in materials can be detected clearly by PL spectroscopy. 22,[23][24] It is a good scientific tool to assess the quality of materials, also many parameters can be calculated from PL spectra.…”

Preferential sublimation along threading dislocations in InGaN/GaN single quantum well for improved photoluminescence

“…28 Similarly, a high temperature thermal treatment of GaN layers can be applied to induce the porosification of the layers under a H2 atmosphere in a hydride vapor phase epitaxy reactor or a metal-organic vapor-phase epitaxy reactor, 29,30 or alternatively under a N2 atmosphere in a resistance furnace 31 or eventually under vacuum in a molecular beam epitaxy reactor after the deposition of a SixNy nanomask. 32,33,34 Through this last approach, we showed that the photoluminescence efficiency at room temperature of highly dislocated GaN layers was strongly increased when they were porosified. We previously attributed this improvement to the preferential sublimation of GaN around dislocations but with only indirect elements supporting this hypothesis.…”