Excitonic emission dynamics at cryogenic- and above room temperature in high brightness sub-micron fin LED and Lasers

2021 ◽  
Author(s):  
Babak Nikoobakht ◽  
Yuqin Zong ◽  
Amit Agrawal ◽  
Michael Shur
Keyword(s):  
Room Temperature ◽  
High Brightness ◽  
Excitonic Emission

scholarly journals High brightness laser based on Yb:YAG MOPA chain and adaptive optics system at room temperature

2018 ◽  
Vol 26 (11) ◽  
pp. 14592 ◽  
Author(s):  
Liu Xu ◽  
Yingchen Wu ◽  
Yinglei Du ◽  
Dan Wang ◽  
Xiangchao An ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Room Temperature ◽  
High Brightness ◽  
Adaptive Optics System

Tailored defect-induced sharp excitonic emission from microcrystalline CuI and its ab initio validation

2014 ◽  
Vol 2 (32) ◽  
pp. 6592-6600 ◽  
Author(s):  
Swati Das ◽  
Subhajit Saha ◽  
Dipayan Sen ◽  
Uttam Kumar Ghorai ◽  
Kalyan Kumar Chattopadhyay
Keyword(s):  
Thin Films ◽  
Ab Initio ◽  
Chemical Reaction ◽  
Room Temperature ◽  
Iodine Concentration ◽  
Excitonic Emission ◽  
Wet Chemical

Iodine concentration modulated free excitonic emission of CuI thin films developed by wet chemical reaction at room temperature.

scholarly journals Room-temperature excitonic emission with a phonon replica from graphene nanosheets deposited on Ni-nanocrystallites/Si-nanoporous pillar array

2018 ◽  
Vol 5 (8) ◽  
pp. 172238
Author(s):  
Zhaojun Tang ◽  
Tingting Xu ◽  
Sen Li ◽  
Zhifeng Shi ◽  
Xinjian Li
Keyword(s):  
Carrier Transport ◽  
Room Temperature ◽  
Graphene Nanosheets ◽  
Chemical Vapour ◽  
Visible Region ◽  
Phonon Replica ◽  
Pillar Array ◽  
Long Term Stability ◽  
Excitonic Emission ◽  
Excitonic Recombination

Graphene nanosheets (GNSs) were grown on a Si nanoporous pillar array (Si-NPA) via chemical vapour deposition, using a thin layer of pre-deposited Ni nanocrystallites as catalyst. GNSs were determined to be of high quality and good dispersivity, with a typical diameter size of 15 × 8 nm. Light absorption measurements showed that GNSs had an absorption band edge at 3.3 eV. They also showed sharp and regular excitonic emitting peaks in the ultraviolet and visible region (2.06–3.6 eV). Moreover, phonon replicas with long-term stability appeared with the excitonic peaks at room temperature. Temperature-dependent photoluminescence from the GNSs revealed that the excitonic emission derived from free and bound excitonic recombination. A physical model based on band energy theory was constructed to analyse the carrier transport of GNSs. The Ni nanocrystallites on Si-NPA, which acted as a metal-enhanced fluorescence substrate, were supposed to accelerate the excitonic recombination of GNSs and enhanced the measured emission intensity. Results of this study would be valuable in determining the luminescence mechanism of GNSs and could be applied in real-world optoelectronic devices.

scholarly journals High Brightness Room Temperature III-Nitride Based Single Photon Source.

2016 ◽  
Author(s):  
Ganapathi Subramanian Subramania ◽  
Patrick Duke Anderson ◽  
Daniel Koleske
Keyword(s):  
Room Temperature ◽  
Single Photon ◽  
Single Photon Source ◽  
High Brightness ◽  
Photon Source

One-pot room temperature synthesizing Cu- and Mn-doped ZnSe nanocrystals by a rapid photochemical method

2016 ◽  
Vol 30 (11) ◽  
pp. 1650227 ◽  
Author(s):  
A. R. Bahador ◽  
M. Molaei ◽  
M. Karimipour
Keyword(s):  
Room Temperature ◽  
Photochemical Synthesis ◽  
Trap States ◽  
One Pot ◽  
X Ray ◽  
Excitonic Emission ◽  
Ft Ir ◽  
Pl Intensity ◽  
Mn Doped ◽  
Znse Nanocrystals

In this work, a one-pot, rapid, green and room temperature photochemical synthesis of transition metal (TM; Cu, Mn)-doped ZnSe nanocrystals (NCs) was reported. NCs were successfully characterized using Fourier transform-infrared (FT-IR), photoluminescence (PL) and UV-Visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), X-ray diffractometry (XRD) and energy dispersive X-ray spectra (EDX). FT-IR spectra confirmed the capping of ZnSe by thioglycolic acid (TGA) molecules. XRD and TEM analysis demonstrated zinc blend phase NCs with an average size of around 3 nm. Band gap of ZnSe NCs was about 3.6 eV which it was decreased by increasing the illumination time. PL spectra of ZnSe NCs showed a broad emission with two peaks located at 380 nm and 490 nm related to excitonic and trap states emission, respectively. For ZnSe:Cu NCs, excitonic emission disappeared completely and PL intensity of trap states emission increased with the increase in the Cu[Formula: see text] ion concentration so that for precursor ratio of Cu:Zn 1%, optimal value of PL intensity was obtained. For ZnSe:Mn NCs, the excitonic emission decreased gradually with the increase in the impurity concentration whereas trap state emission increased. Moreover, a peak about 590 nm was appeared from 4T1-6A1 transition of the Mn[Formula: see text] impurity, demonstrating the Mn incorporation inside the ZnSe NCs structure.

scholarly journals Bright Silicon Carbide Single-Photon Emitting Diodes at Low Temperatures: Toward Quantum Photonics Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3177
Author(s):  
Igor A. Khramtsov ◽  
Dmitry Yu. Fedyanin
Keyword(s):  
Silicon Carbide ◽  
Spectral Properties ◽  
Room Temperature ◽  
Single Photon ◽  
Numerical Approach ◽  
Color Centers ◽  
Electrical Excitation ◽  
High Brightness ◽  
Quantum Photonics ◽  
First Time

Color centers in silicon carbide have recently emerged as one of the most promising emitters for bright single-photon emitting diodes (SPEDs). It has been shown that, at room temperature, they can emit more than 109 photons per second under electrical excitation. However, the spectral emission properties of color centers in SiC at room temperature are far from ideal. The spectral properties could be significantly improved by decreasing the operating temperature. However, the densities of free charge carriers in SiC rapidly decrease as temperature decreases, which reduces the efficiency of electrical excitation of color centers by many orders of magnitude. Here, we study for the first time the temperature characteristics of SPEDs based on color centers in 4H-SiC. Using a rigorous numerical approach, we demonstrate that although the single-photon electroluminescence rate does rapidly decrease as temperature decreases, it is possible to increase the SPED brightness to 107 photons/s at 100 K using the recently predicted effect of hole superinjection in homojunction p-i-n diodes. This gives the possibility to achieve high brightness and good spectral properties at the same time, which paves the way toward novel quantum photonics applications of electrically driven color centers in silicon carbide.

scholarly journals Robust B-exciton emission at room temperature in few-layers of MoS2:Ag nanoheterojunctions embedded into a glass matrix

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Abdus Salam Sarkar ◽  
Ioannis Konidakis ◽  
Ioanna Demeridou ◽  
Efthymis Serpetzoglou ◽  
George Kioseoglou ◽  
...  
Keyword(s):  
Glass Matrix ◽  
Room Temperature ◽  
External Factors ◽  
Plasmon Coupling ◽  
Two Dimensional ◽  
Time Resolved ◽  
Exciton Emission ◽  
Excitonic Emission ◽  
And Control ◽  
Significant Effort

Abstract Tailoring the photoluminescence (PL) properties in two-dimensional (2D) molybdenum disulfide (MoS2) crystals using external factors is critical for its use in valleytronic, nanophotonic and optoelectronic applications. Although significant effort has been devoted towards enhancing or manipulating the excitonic emission in MoS2 monolayers, the excitonic emission in few-layers MoS2 has been largely unexplored. Here, we put forward a novel nano-heterojunction system, prepared with a non-lithographic process, to enhance and control such emission. It is based on the incorporation of few-layers MoS2 into a plasmonic silver metaphosphate glass (AgPO3) matrix. It is shown that, apart from the enhancement of the emission of both A- and B-excitons, the B-excitonic emission dominates the PL intensity. In particular, we observe an almost six-fold enhancement of the B-exciton emission, compared to control MoS2 samples. This enhanced PL at room temperature is attributed to an enhanced exciton–plasmon coupling and it is supported by ultrafast time-resolved spectroscopy that reveals plasmon-enhanced electron transfer that takes place in Ag nanoparticles-MoS2 nanoheterojunctions. Our results provide a great avenue to tailor the emission properties of few-layers MoS2, which could find application in emerging valleytronic devices working with B excitons.

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