- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Hybrid perovskite light emitting diodes under intense electrical excitation
摘要： Hybrid perovskite semiconductors represent a promising platform for color-tunable light emitting diodes (LEDs) and lasers; however, the behavior of these materials under the intense electrical excitation required for electrically-pumped lasing remains unexplored. Here, we investigate methylammonium lead iodide-based perovskite LEDs under short pulsed drive at current densities up to 620 A cm?2. At low current density (J < 10 A cm?2), we ?nd that the external quantum ef?ciency (EQE) depends strongly on the time-averaged history of the pulse train and show that this curiosity is associated with slow ion movement that changes the internal ?eld distribution and trap density in the device. The impact of ions is less pronounced in the high current density regime (J > 10 A cm?2), where EQE roll-off is dominated by a combination of Joule heating and charge imbalance yet shows no evidence of Auger loss, suggesting that operation at kA cm?2 current densities relevant for a laser diode should be within reach.
关键词： ion movement,electrical excitation,lasers,Auger loss,light emitting diodes,Hybrid perovskite semiconductors,Joule heating,external quantum efficiency,charge imbalance
更新于2025-09-23 15:21:01
-
Selective terahertz emission due to electrically excited 2D plasmons in AlGaN/GaN heterostructure
摘要： Terahertz radiation emission from an electrically excited AlGaN/GaN heterostructure with a surface metal grating was studied under conditions of two-dimensional (2D) electron heating by the lateral electric field. Intensive peaks related to nonequilibrium 2D plasmons were revealed in the terahertz emission spectra with up to 4 times selective amplification of the radiation emission in the vicinity of 2D plasmon resonance. This selective emission was shown to be frequency-controllable by the grating period. Exact spectral positions of the 2D plasmon resonances were preliminarily experimentally detected with the help of equilibrium transmission spectra measured at various temperatures. The resonance positions are in a satisfactory agreement with the results of theoretical simulation of the transmission spectra performed using a rigorous solution of Maxwell’s equations. The effective temperature of hot 2D electrons was determined by means of I–V characteristics and their analysis using the power balance equation. It was shown that for a given electric field, the effective temperature of nonequilibrium 2D plasmons is close to the hot 2D electron temperature. The work may have applications in GaN-based electrically pumped emitters of terahertz radiation.
关键词： electrical excitation,terahertz radiation,metal grating,AlGaN/GaN heterostructure,2D plasmons
更新于2025-09-11 14:15:04
-
Coherent surface plasmon amplification through the dissipative instability of 2D direct current
摘要： We propose an original concept for on-chip excitation and amplification of surface plasmon polaritons. Our approach, named nanoresotron, utilizes the collective effect of dissipative instability of a 2D direct current flowing in vicinity of a metal surface. The instability arises through the excitation of self-consistent plasma oscillations and results in the creation of a pair of collective surface electromagnetic modes in addition to conventional plasmon resonances. We derive the dispersion equations for these modes using self-consistent solutions of Maxwell’s and 2D hydrodynamics equations. We find that the phase velocities of these new collective modes are close to the drift velocity of 2D electrons. We demonstrate that the slow mode is amplified while the fast mode exhibits absorption. Estimates indicate that very high gain are attainable, which makes the nanoresotron a promising scheme to electrically excite and regenerate surface plasmon polaritons.
关键词： dissipative instability of DC current,electrical excitation of nanoantenna,self-consistent 2D plasma oscillation
更新于2025-09-09 09:28:46