Photon color conversion enhancement of colloidal quantum dots inserted into a subsurface laterally-extended GaN nano-porous structure in an InGaN/GaN quantum-well template

Abstract

To improve the color conversion performance, we study the nanoscale-cavity effects on the emission efficiency of a colloidal quantum dot (QD) and the Förster resonance energy transfer (FRET) from quantum well (QW) into QD in a GaN porous structure (PS). For this study, we insert green-emitting QD (GQD) and red-emitting QD (RQD) into the fabricated PSs in a GaN template and a blue-emitting QW template, and investigate the behaviors of the photoluminescence (PL) decay times and the intensity ratios of blue, green, and red lights. In the PS samples fabricated on the GaN template, we observe the efficiency enhancements of QD emission and the FRET from GQD into RQD, when compared with the samples of surface QDs, which is attributed to the nanoscale-cavity effect. In the PS samples fabricated on the QW template, the FRET from QW into QD is also enhanced. The enhanced FRET and QD emission efficiencies in a PS result in an improved color conversion performance. Because of the anisotropic PS in the sample surface plane, the polarization dependencies of QD emission and FRET are observed.

Advancements in Micro-LED Performance through Nanomaterials and Nanostructures: A Review

“…Moreover, compared to other nanostructures, nanorod structures can save more active area. Additionally, nanorods provide more escape paths for photons, similar to the effect of (d) EL spectra, where "QW-H" represents the structure with nanoholes, "R" and "G" denote red and green Ds, respectively, and "RN" and "GN" represent Ag NPs whose absorption resonance peaks match the emission wavelengths of red and green QDs, respectively [93]. Reprinted with permission from ref.…”

“…When bot red and green QDs are present, the LSP matching the emission wavelength of the red QD contributes more prominently to the overall CCE. EL spectra, where "QW-H" represents the structure with nanoholes, "R" and "G" denote red and green Ds, respectively, and "RN" and "GN" represent Ag NPs whose absorption resonance peaks match the emission wavelengths of red and green QDs, respectively [93]. Reprinted with permission from ref.…”

Emission and Förster Resonance Energy Transfer Behaviors of Colloidal Quantum Dots in a Metal Nanohole

“…Then, in the samples with QDs inserted into GaN NHs, all the decay times are reduced from the corresponding values in the surface samples. Such reductions are attributed to the enhancements of QD emission e ciencies caused by the nanoscale-cavity effect [3][4][5]. In sample NH/GN-GQD + RQD, the green-light decay time further decreases due to the FRET process.…”

“…In the case of locating a light emitter inside a small cavity, the near-eld version of the Purcell effect can also increase its emission e ciency. Experimental and numerical studies have demonstrated the emission e ciency enhancements of colloidal quantum dots (QDs) when they are inserted into nanoscale cavities, such as a surface nanohole (NH) and a subsurface porous structure [2][3][4]. Such an emission enhancement was generally referred to as the nanoscale-cavity effect.…”

“…For the two reasons above, the study of the emission behavior of a colloidal QD in an Ag or Au nanocavity is important for expanding the application of a QD. Besides the emission e ciency of a single QD, the enhancement of the Förster resonance energy transfer (FRET) from a QD donor into a QD acceptor has been demonstrated when both donor and acceptor are located inside a nanocavity [2][3][4][5]. FRET is a nonradiative near-eld energy transfer process [7], which is an effective mechanism for implementing photon color conversion [8][9][10].…”