A novel hybrid inorganic/organic semiconductor nanostructure has been developed, leading to very efficient nonradiative resonant-energy-transfer (RET) between blue emitting InGaN/GaN multiple quantum wells (MQWs) and a yellow light emitting polymer. The utilization of InGaN/GaN nanorod arrays allows for both higher optical performance of InGaN blue emission and a minimized separation between the InGaN/GaN MQWs and the emitting polymer as a color conversion medium. A significant reduction in decay lifetime of the excitons in the InGaN/GaN MQWs of the hybrid structure has been observed as a result of the nonradiative RET from the nitride emitter to the yellow polymer. A detailed calculation has demonstrated that the efficiency of the nonradiative RET is as high as 73%. The hybrid structure exhibits an extremely fast nonradiative RET with a rate of 0.76 ns(-1), approximately three times higher than the InGaN/GaN MQW nonradiative decay rate of 0.26 ns(-1). It means that the RET dominates the nonradiative processes in the nitride quantum well structure, which can further enhance the overall device performance.

It is crucial to fabricate nano photonic devices such as nanolasers in order to meet the requirements for the integration of photonic and electronic circuits on the nanometre scale. The great difficulty is to break down a bottleneck as a result of the diffraction limit of light. Nanolasers on a subwavelength scale could potentially be fabricated based on the principle of surface plasmon amplification by stimulated emission of radiation (SPASER). However, a number of technological challenges will have to be overcome in order to achieve a SPASER with a low threshold, allowing for a continuous wave (cw) operation at room temperature. We report a nano-SPASER with a record low threshold at room temperature, optically pumped by using a cw diode laser. Our nano-SPASER consists of a single InGaN/GaN nanorod on a thin SiO2 spacer layer on a silver film. The nanorod containing InGaN/GaN multi-quantum-wells is fabricated by means of a cost-effective post-growth fabrication approach. The geometry of the nanorod/dielectric spacer/plasmonic metal composite allows us to have accurate control of the surface plasmon coupling, offering an opportunity to determine the optimal thickness of the dielectric spacer. This approach will open up a route for further fabrication of electrically injected plasmonic lasers.

No abstract

Excitonic recombination dynamics has been investigated on a series of InxGa1−xN/GaN (0.10 ≤ x ≤ 0.30) nanorod (NR) structures with a diameter of ∼220 nm by time-revolved photoluminescence (PL). The NR structures are fabricated by means of a post-growth etching technique. Compared with their corresponding as-grown samples, the time-integrated PL intensities of the NR samples show a remarkable enhancement with a factor of up to 52 at room temperature. The ratios of the radiative to non-radiative recombination lifetime of the NR structures are much less sensitive to temperature than those of their corresponding as-grown samples. This becomes more prominent with increasing indium composition. A distinct delay in transition temperature, where the dominating emission mechanism changes from radiative to non-radiative recombination, has been observed on the NR structures. The great enhancement in optical properties is attributed to both strain relaxation and extra in-plane excitonic confinement due to the nanostructures.

An excellent hybrid III‐nitride/nanocrystal nanohole light‐emitting diode (h‐LED) has been developed utilizing nonradiative resonant energy transfer (NRET) between violet/blue emitting InGaN/GaN multiple quantum wells (MQWs) and various wavelength emitting nanocrystals (NCs) as color‐conversion mediums. InGaN/GaN MQWs are fabricated into nanoholes by soft nanoimprint lithography to minimize the separation between MQWs and NCs. A significant reduction in the decay lifetime of excitons in the MQWs of the hybrid structure has been observed as a result of the NRET from the nitride emitter to NCs. The NRET efficiency of the hybrid structures is obtained from the decay curves, as high as 80%. Moreover, a modified Förster formulation has exhibited that the exciton coupling distance in the hybrid structures is less than the Förster's radius, demonstrating a strong coupling between MQWs and NCs. Finally, based on a systemic optimization for white emission indexes, a series of hybrid ternary complementary color h‐LEDs have been demonstrated with a high color rendering index, up to 82, covering the white light emission at different correlated color temperatures ranging from 2629 to 6636 K, corresponding to warm white, natural white, and cold white.