40
2 Entering a Two-Dimensional Materials World
Fig. 2.12 Examples of 2D photonics, which have made use of optical microcavities in combination
with monolayer TMDCs. a Quantum yield as a function of temperature. Data shown for 300 and 10 K
for three prominent TMDC materials. Reproduced with permission. [72] (Supporting Information)
Copyright 2015 Springer Nature. b Typical detuning series in waterfall representation of reflectivity
spectra recorded from a 2D–microcavity system in the strong light–matter coupling regime. The
anticrossing behaviour is a signature of the establishment of (cavity–)polariton modes, hybrids of
light and matter, also known as excitons dressed with photons. Accordingly, the extracted mode
energies with characteristic Rabi splitting (here of 46 meV at a finite angle situation) are displayed
in (c). b, c Adapted with permission. [64] Copyright 2014 Springer Nature. d Double-logarithmic
input–output curve for a 2D microlaser (red) in comparison to the material’s spontaneous emission
(SE, violet symbols). Reproduced with permission. [70] Copyright 2015 Springer Nature
Using scattering-type optical scanning near-field microscopy (s-SNOM, see
raster-scanned image in Fig. 2.13d), reflection-contrast measurements and luminescence (μ-PL) investigations, the successful demonstration of a markedly enhanced
out-of-plane emission from such monolayer structure indicates the effectiveness of
this CIDBROM structure; such structure indeed served as a model system for in-plane
confinement and enhanced vertical PL extraction, as well as local, spectrally-sensitive
absorption enhancement [156].
These experiments were performed with eyes towards future waveguide-coupled
on-chip applications, for example, for optical integrated circuitry and valleytronics. Both, micro/nano-sized 2D LEDs and 2D photovoltaics may benefit from these
established interference-based optical confinement approaches. The author’s ongoing investigations aim at the demonstration of tailored emission control of out-ofplane dipole resonances (as a stronger confinement is predicted by simulated fields
for out-of-plane than in-plane fields, see Supporting Information of [156]), such
as interlayer excitons in heterostructures and z-mode (out-of-plane dipole, “grey”)
excitons in monolayers, as well as at improved absorption/light–matter-interaction
capabilities, e.g. for photovoltaics or nonlinear optics.
2 Entering a Two-Dimensional Materials World
Fig. 2.12 Examples of 2D photonics, which have made use of optical microcavities in combination
with monolayer TMDCs. a Quantum yield as a function of temperature. Data shown for 300 and 10 K
for three prominent TMDC materials. Reproduced with permission. [72] (Supporting Information)
Copyright 2015 Springer Nature. b Typical detuning series in waterfall representation of reflectivity
spectra recorded from a 2D–microcavity system in the strong light–matter coupling regime. The
anticrossing behaviour is a signature of the establishment of (cavity–)polariton modes, hybrids of
light and matter, also known as excitons dressed with photons. Accordingly, the extracted mode
energies with characteristic Rabi splitting (here of 46 meV at a finite angle situation) are displayed
in (c). b, c Adapted with permission. [64] Copyright 2014 Springer Nature. d Double-logarithmic
input–output curve for a 2D microlaser (red) in comparison to the material’s spontaneous emission
(SE, violet symbols). Reproduced with permission. [70] Copyright 2015 Springer Nature
Using scattering-type optical scanning near-field microscopy (s-SNOM, see
raster-scanned image in Fig. 2.13d), reflection-contrast measurements and luminescence (μ-PL) investigations, the successful demonstration of a markedly enhanced
out-of-plane emission from such monolayer structure indicates the effectiveness of
this CIDBROM structure; such structure indeed served as a model system for in-plane
confinement and enhanced vertical PL extraction, as well as local, spectrally-sensitive
absorption enhancement [156].
These experiments were performed with eyes towards future waveguide-coupled
on-chip applications, for example, for optical integrated circuitry and valleytronics. Both, micro/nano-sized 2D LEDs and 2D photovoltaics may benefit from these
established interference-based optical confinement approaches. The author’s ongoing investigations aim at the demonstration of tailored emission control of out-ofplane dipole resonances (as a stronger confinement is predicted by simulated fields
for out-of-plane than in-plane fields, see Supporting Information of [156]), such
as interlayer excitons in heterostructures and z-mode (out-of-plane dipole, “grey”)
excitons in monolayers, as well as at improved absorption/light–matter-interaction
capabilities, e.g. for photovoltaics or nonlinear optics.