Control of spontaneous emission rate in lead halide perovskite film on hyperbolic metamaterial

Hyperbolic metamaterials represent a class of nanophotonic architectures with the possibility of controlling density of optical states. Due to this property, hyperbolic metamaterials can be employed as meta-electrodes in optoelectronic devices. On the other hand, lead halide perovskites have several promising properties for application in light-emitting devices. Moreover, a perovskite film is easily deposited on a hyperbolic metamaterial surface. Here, we theoretically show how to accelerate radiative recombination in a perovskite film with a hyperbolic metamaterial. This effect can be applied in light-emitting devices, where radiative recombination is extremely important.

Quantum interference of spontaneous-emission channels near the surface of Bi2Se3

We show that the quantum interference between two spontaneous emission channels can be significantly enhanced when a three-level V-type atom is placed near the surface of the topological insulator [Formula: see text]. The enhancement of quantum interference is a result of the strong dependence of the spontaneous emission rate on the orientation of an atomic dipole relative to surface of the [Formula: see text] at the frequencies of polaritonic-type excitations.

Temperature Dependence of the Local Field Effect in YAG:Ce3+ Nanocomposites

The spontaneous emission rate (SER) of a chromophore in a nanoparticle (NP) is determined by the modification of the electric field by its environment. Previous studies of this local field...

Controlling Spontaneous Emission from Perovskite Nanocrystals with Metal-Emitter-Metal Nanostructures

We show the enhancement in the intensity and emission rate of perovskite cesium lead bromide (CsPbBr3) and formamidinium lead bromide (FAPbBr3) nanocrystals in the presence of single and double gold layer cavities, which we refer to as Metal-Emitter (ME) and Metal-Emitter-Metal (MEM) nanostructures. Up to 1.9-fold photoluminescence intensity and up to 5.4-fold emission rate enhancements were obtained for FAPbBr3 nanocrystals confined by double gold layers, which are attributed to plasmonic confinement from the gold layers. The experimentally obtained values are validated by analytical calculations and electromagnetic simulations. Such an effective method of manipulation of the spontaneous emission rate by simple plasmonic nanostructures can be utilized in sensing and detection applications.

Controlling Spontaneous Emission from Perovskite Nanocrystals with Metal-Emitter-Metal Nanostructures

We show the enhancement in the intensity and emission rate of perovskite cesium lead bromide (CsPbBr3) and formamidinium lead bromide (FAPbBr3) nanocrystals in the presence of single and double gold layer cavities, which we refer to as Metal-Emitter (ME) and Metal-Emitter-Metal (MEM) nanostructures. Up to 1.9-fold photoluminescence intensity and up to 5.4-fold emission rate enhancements were obtained for FAPbBr3 nanocrystals confined by double gold layers, which are attributed to plasmonic confinement from the gold layers. The experimentally obtained values are validated by analytical calculations and electromagnetic simulations. Such an effective method of manipulation of the spontaneous emission rate by simple plasmonic nanostructures can be utilized in sensing and detection applications.

AlGaN-Delta-GaN Quantum Well for DUV LEDs

AlGaN-delta-GaN quantum well (QW) structures have been demonstrated to be good candidates for the realization of high-efficiency deep-ultraviolet (DUV) light-emitting diodes (LEDs). However, such heterostructures are still not fully understood. This study focuses on investigation of the optical properties and efficiency of the AlGaN-delta-GaN QW structures using self-consistent six-band k⸱p modelling and finite difference time domain (FDTD) simulations. Structures with different Al contents in the AlxGa1−xN sub-QW and AlyGa1−yN barrier regions are examined in detail. Results show that the emission wavelength (λ) can be engineered through manipulation of delta-GaN layer thickness, sub-QW Al content (x), and barrier Al content (y), while maintaining a large spontaneous emission rate corresponding to around 90% radiative recombination efficiency (ηRAD). In addition, due to the dominant transverse-electric (TE)-polarized emission from the AlGaN-delta-GaN QW structure, the light extraction efficiency (ηEXT) is greatly enhanced when compared to a conventional AlGaN QW. Combined with the large ηRAD, this leads to the significant enhancement of external quantum efficiency (ηEQE), indicating that AlGaN-delta-GaN structures could be a promising solution for high-efficiency DUV LEDs.