2 research outputs found
Integration of Nanoscale Light Emitters and Hyperbolic Metamaterials: An Efficient Platform for the Enhancement of Random Laser Action
Hyperbolic metamaterials have emerged
as novel materials with exciting
functionalities, especially for optoelectronic devices. Here, we provide
the first attempt to integrate hyperbolic metamaterials with light
emitting nanostructures, which enables to strongly enhance random
laser action with reduced lasing threshold. Interestingly, the differential
quantum efficiency can be enhanced by more than four times. The underlying
mechanism can be interpreted well based on the fact that the high-<i>k</i> modes excited by hyperbolic metamaterials can greatly
increase the possibility of forming close loops decreasing the energy
consumption for the propagation of scattered photons in the matrix.
In addition, out-coupled propagation of the high-<i>k</i> modes reaches to the far-field without being trapped inside the
metamaterials due to the coupling with the random distribution of
light emitting nanoparticles also plays an important role. Electromagnetic
simulations derived from the finite-difference time-domain (FDTD)
method are executed to support our interpretation. Realizing strong
enhancement of laser action assisted by hyperbolic metamaterials provides
an attractive, very simple and efficient scheme for the development
of high performance optoelectronic devices, including phototransistors,
and many other solid state lighting systems. Besides, because of increasing
light absorption assisted by hyperbolic metamaterials structure, our
approach shown is also useful for the application of highly efficient
solar cells
Plasmonic Carbon-Dot-Decorated Nanostructured Semiconductors for Efficient and Tunable Random Laser Action
Carbon
dots have emerged as popular materials in various research fields,
including biological and photovoltaic areas, while significant reports
are lacking related to their applications in laser devices, which
play a significant role in our daily life. In this work, we demonstrate
the first controllable random laser assisted by the surface plasmon
effect of carbon dots. Briefly, carbon dots derived from candle soot
are randomly deposited on the surface of gallium nitride (GaN) nanorods
to enhance the ultraviolet fluorescence of GaN and generate plasmonically
enhanced random laser action with coherent feedback. Furthermore,
potentially useful functionalities of tunable lasing threshold and
controllable optical modes are achieved by adjusting the numbers of
carbon dots, enabling applications in optical communication and identification
technologies. In addition to providing an efficient alternative for
plasmonically enhanced random laser devices with simple fabrication
and low cost, our work also paves a useful route for the application
of environmentally friendly carbon dots in optoelectronic devices