Room Temperature Current Injection Polariton Light Emitting Diode with a Hybrid Microcavity

Abstract

The strong light-matter interaction within a semiconductor high-Q microcavity has been used to produce half-matter/half-light quasiparticles, exciton-polaritons. The exciton-polaritons have very small effective mass and controllable energy-momentum dispersion relation. These unique properties of polaritons provide the possibility to investigate the fundamental physics including solid-state cavity quantum electrodynamics, and dynamical Bose-Einstein condensates (BECs). Thus far the polariton BEC has been demonstrated using optical excitation. However, from a practical viewpoint, the current injection polariton devices operating at room temperature would be most desirable. Here we report the first realization of a current injection microcavity GaN exciton-polariton light emitting diode (LED) operating under room temperature. The exciton-polariton emission from the LED at photon energy 3.02 eV under strong coupling condition is confirmed through temperature-dependent and angle-resolved electroluminescence spectra.

Room-Temperature Observation of Trapped Exciton-Polariton Emission in GaN/AlGaN Microcavities with Air-Gap/III-Nitride Distributed Bragg Reflectors

“…The dispersion DSP1 formed by the large momentum states in Figure 3(a) is also reproduced in Figure 3(b). This confirms that the quantized modes in Figure 3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 obtained Rabi-splitting (Ω) for the result shown in Figure 3(c) is Ω = 2g = 66 meV, which is relatively larger than previous reports [35][36][37][38][39][40] and is mainly attributed to the usage of air-gap DBRs. 43 Next we estimate the exciton oscillator strength, B, using a simple equation modified from a bulk-active-layer case, 46,47 …”

“…Indeed, exciton-polariton luminescence [34][35][36] and even lasing/condensation [37][38][39][40] has been realized at room temperature in GaN-based cavities. However, trapped exciton-polariton states and trapped photon states have not yet been reported in III-nitride DBR MCs, due to difficulties in both the patterning process and obtaining a sufficient degree of trapping when using III-nitride DBR MCs.…”

Electrically Pumped III-N Microcavity Light Emitters Incorporating an Oxide Confinement Aperture

“…III-Nitride based materials are highly attractive for making vertical microcavity (MC) light emitters such as strongly coupled polariton lasers and conventional vertical-cavity surface-emitting lasers (VCSELs) due to their large exciton binding energies and wide spectra tuning range in the ultraviolet-visible region [1][2][3][4][5][6][7][8][9][10][11][12]. So far, electrically pumped polariton emitters and conventional VCSELs have been demonstrated in III-nitride based MCs at room temperature (RT).…”

Direct evidence of Rabi oscillations and antiresonance in a strongly coupled organic microcavity

“…This antiresonance selectively probes the uncoupled exciton excitation, and its observation uncovers the coherent and ultrafast exchange of energy between the optically excited cavity and the J-aggregate excitons, as confirmed by transfer matrix calculations. [7,8] have already been demonstrated. The microscopic origin of these phenomena lies in the coherent interaction between excitons and cavity photons, via coupling of the excitonic transition dipole moment to fluctuating (vacuum) electromagnetic fields stored within the cavity.…”

“…Applications such as the polariton amplifier [5,6] and a polariton light-emitting diode [7,8] have already been demonstrated. The microscopic origin of these phenomena lies in the coherent interaction between excitons and cavity photons, via coupling of the excitonic transition dipole moment to fluctuating (vacuum) electromagnetic fields stored within the cavity.…”