Experiments have shown that the light-emission efficiency of indium gallium nitride [(In,Ga)N] light-emitting diodes improves with increasing indium concentration. It is widely thought that compositional fluctuations ...
详细信息
Experiments have shown that the light-emission efficiency of indium gallium nitride [(In,Ga)N] light-emitting diodes improves with increasing indium concentration. It is widely thought that compositional fluctuations due to indium incorporation suppress diffusion of carriers to nonradiative centers, thus leading to defect-insensitive emission. However, recent experiments have challenged this hypothesis by revealing unexpectedly long diffusion lengths at room temperature. Here, we demonstrate an alternative mechanism involving the correlated reduction in radiative and nonradiative recombination rates that explains the increase in light-emission efficiency of (In,Ga)N with increasing indium concentration, without invoking the suppression of carrier diffusion. Our analysis challenges the notion that carrier localization gives rise to defect tolerance in (In,Ga)N.
This study investigated the effects of population growth on the performance of Nkowankowa Wastewater Treatment Works (WWTW) in Mopani District Municipality, South Africa. Four-year (2020–2023) effluent quality data o...
详细信息
In this paper, Graphene Aerogel (GA) is prepared and investigated for its potential employment for solar energy harvesting applications. GA can be applied in solar cells applications as an absorption material and as a...
详细信息
High Power Impulse Magnetron Sputtering (HIPIMS) has emerged as a promising technique for the deposition of thin films with superior properties. In this study, HIPIMS was combined with a positive target bias (Kick vol...
详细信息
ISBN:
(数字)9798350385175
ISBN:
(纸本)9798350385182
High Power Impulse Magnetron Sputtering (HIPIMS) has emerged as a promising technique for the deposition of thin films with superior properties. In this study, HIPIMS was combined with a positive target bias (Kick voltage) process to enhance AlN film quality further. Aluminum Nitride (AlN) thin films were deposited using this method and characterized using Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD). The thermal properties of the films were investigated using Frequency Domain Thermoreflectance (FDTR). The results show that the HIPIMS plus Kick process significantly improves the film quality, leading to enhanced thermal conductivity (112 W/m·K) compared to conventional techniques. This work demonstrates the potential of HIPIMS in producing high-quality thin films with improved thermal properties, making it suitable for various applications in electronics and thermal management.
Inheriting the energy storage mechanism of supercapacitors and rechargeable ion batteries, zinc ion capacitors (ZICs), greatly increase the energy density at high power without sacrificing life. However, the sluggish ...
详细信息
We demonstrate in situ control of the elastic wave polarization in a surface acoustic wave (SAW). It allows us to create highly reconfigurable SAW microfluidics that can be switched on demand between the acoustohydrod...
详细信息
We demonstrate in situ control of the elastic wave polarization in a surface acoustic wave (SAW). It allows us to create highly reconfigurable SAW microfluidics that can be switched on demand between the acoustohydrodynamic (AHD) regime and electrohydrodynamic (EHD) regime for manipulating particles and cells. The control of wave polarization comes from our experimental and theoretical identification of an unexpected shear-horizontal (SH) wave mode in a conventional Rayleigh (R) wave design, which is stereotyped to excite only vertically polarized Rayleigh SAWs. The SH wave mode is predominantly horizontally polarized and can be selectively excited to propagate in the same direction as the Rayleigh SAW. Such a selective wave generation between the SH mode and R mode allows for reconfiguration between AHD and EHD regimes that leads to unprecedented colloidal patterns and assembly dynamics. Such a reconfiguration of the particle manipulation mechanism can be explained by the controllable competition or synergism between the coexisting acoustic and electric fields. Remarkably, in the EHD regime, a virtual zero-boundary electric quadrupole is created, and a novel colloidal diamond-shaped assembly is observed in this piezoelectric-quadrupole trap, which was rarely reported in acoustic or electric microfluidics. The presented in situ control of polarization revolutionizes our understanding of SAW and acoustofluidics, expands its potential by assuming the advantages of AHD and EHD on demand, and inspires new strategies in micro- and nanoscale manufacturing and manipulation, with applications beyond fundamental scientific interest.
Confining lithium (Li) deposition in three-dimensional scaffold is commonly employed to suppress Li dendrite and enhance the cycling stability of next generation Li metal batteries (LMBs). However, the efficiency of t...
详细信息
In this work, we demonstrate the feasibility of applying electric pulses to heal surface cracks on Ni-based GH4169 alloy under compressive load. There exists an incubation time for the onset of the healing of a crack,...
详细信息
CoNiMg4Al2 catalysts were synthesized using two different methods: solution blow spinning to produce nanofibers (NF), and co-precipitation to produce hydrotalcite precursors (HT). Part of the hydrotalcite sample was g...
详细信息
暂无评论