Abstract
GaN-based UV light-emitting devices suffer from low efficiency. To mitigate this issue, we hybridized GaN nanowires (NWs) grown on Si substrates by plasma-assisted molecular beam epitaxy with solution-processed p-type MnO quantum dots (QDs) characterized by a wider band gap (∼5 eV) than that of GaN. Further investigations reveal that the photoluminescence intensity of the GaN NWs increases up to ∼3.9-fold (∼290%) after functionalizing them with p-MnO QDs, while the internal quantum efficiency is improved by ∼1.7-fold. Electron energy loss spectroscopy (EELS) incorporated into transmission electron microscopy reveals an increase in the density of states in QD-decorated NWs compared to the bare ones. The advanced optical and EELS analyses indicate that the energy transfer from the wider band gap p-MnO QDs to n-GaN NW can lead to substantial emission enhancement and greater radiative recombination contribution because of the good band alignment between MnO QDs and GaN NWs. This work provides valuable insights into an environmentally friendly strategy for improving UV device performance.
Highlights
Technologies based on GaN and related III-nitrides are widely used in several applications, such as light-emitting diodes (LEDs), laser diodes, photodetectors, and high-power and high-frequency devices,[1,2] owing to the unique electrical and optical properties of these materials, such as direct band gap, wide spectral tunability, good conductivity, and durability in harsh environments
The scanning TEM (STEM) image of a single GaN NW decorated by MnO quantum dots (QDs) through the drop-casting method is shown in Figure 1c
We reported on the first study as a part of which the UV emission of NWs was enhanced significantly by functionalizing them by p-MnO QDs characterized by a wider band gap to transfer the energy from the QDs to GaN
Summary
Technologies based on GaN and related III-nitrides are widely used in several applications, such as light-emitting diodes (LEDs), laser diodes, photodetectors, and high-power and high-frequency devices,[1,2] owing to the unique electrical and optical properties of these materials, such as direct band gap, wide spectral tunability, good conductivity, and durability in harsh environments. We explored new wide band gap (>4.5 eV) crystalline p-type manganese oxide quantum dots (p-MnO QDs) synthesized by a solutionprocessed femtosecond laser ablation in liquid (FLAL) technique.[16,17] the effect of GaN NWs hybridized with these p-MnO QDs that are characterized by wider band gap (∼4.8 eV, located in the deep UV spectral region) has not yet been investigated These gaps in extant knowledge have prompted this investigation, as a part of which a novel strategy based on hybridizing p-type MnO QDs with GaN by a simple and costeffective drop-casting method was adopted to improve the optical GaN efficiency through energy transfer (ET) from QDs to GaN. Note that no PL measurements were acquired within the first 30 min after drop-casting the solution-processed MnO QDs on GaN NWs as our prior examinations indicated that this is sufficient for ensuring that ethanol is evaporated completely
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
