Observation of monochromatic and coherent luminescence from nanocavities of GaN nanowall network

Scaling-down the size of semiconductor cavity lasers and engineering their electromagnetic environment in the Purcell regime can bring about spectacular advance in nanodevices fabrication. We report here an unprecedented observation of a coherent Cathodoluminescence from GaN nanocavities (20–100 nm). Incident lower energy (< 15 kV) electron beams excite the band edge UV emission from the walls of the network whereas for higher energies, the emitted photons are spontaneously down converted into NIR and preferentially emerge from the nanocavities. Non-centrosymmetric structure of GaN and its nanowall geometry together facilitate this unique observation which is substantiated by our numerical results. At cryogenic temperatures, an intense and narrow laser-like NIR beam emanates out of the nanocavities. The work promises the possibility of fabrication of very high density (over 108/cm2) cavity lasers that are addressable by simple deflection and tuning of incident electron beams.

Novel polyethyleneimine functionalized chitosan–lignin composite sponge with nanowall-network structures for fast and efficient removal of Hg(ii) ions from aqueous solution

An environmental-friendly polyethyleneimine functionalized chitosan–lignin composite sponge with interconnected nanowall-network structures is feasibly fabricated for rapidly and selectively removing Hg(ii) ions from aqueous solution.

Charge transfer-induced enhancement of a Raman signal in a hybrid Ag–GaN nanostructure

The optical properties and electronic band structure of Ag nanoparticles dispersed on a GaN nanowall network were studied. High metal like surface conductivity was revealed, and charge transfer between Ag and GaN was involved in the enhancement of Raman signals.

Architecting pyrediyne nanowalls with improved inter-molecular interactions, electronic features and transport characteristics

Highly stabilized molecular interactions and bulk transport characteristics are achieved through the synthesis of an ultrathin 2D nanowall network of pyrediyne.