Broadband Near‐Infrared Garnet Phosphors with Near‐Unity Internal Quantum Efficiency

2020 ◽  
Vol 8 (12) ◽  
pp. 2000296 ◽  
Author(s):  
Endale T. Basore ◽  
Wenge Xiao ◽  
Xiaofeng Liu ◽  
Jianhong Wu ◽  
Jianrong Qiu
Keyword(s):  
Quantum Efficiency ◽  
Near Infrared ◽  
Internal Quantum Efficiency

Red/Near‐Infrared Thermally Activated Delayed Fluorescence OLEDs with Near 100 % Internal Quantum Efficiency

2019 ◽  
Vol 131 (41) ◽  
pp. 14802-14807 ◽  
Author(s):  
Jia‐Xiong Chen ◽  
Wen‐Wen Tao ◽  
Wen‐Cheng Chen ◽  
Ya‐Fang Xiao ◽  
Kai Wang ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Near Infrared ◽  
Internal Quantum Efficiency ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated

Red/Near‐Infrared Thermally Activated Delayed Fluorescence OLEDs with Near 100 % Internal Quantum Efficiency

2019 ◽  
Vol 58 (41) ◽  
pp. 14660-14665 ◽  
Author(s):  
Jia‐Xiong Chen ◽  
Wen‐Wen Tao ◽  
Wen‐Cheng Chen ◽  
Ya‐Fang Xiao ◽  
Kai Wang ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Near Infrared ◽  
Internal Quantum Efficiency ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated

Quantum Confinement Modeling and Simulation for Quantum Well Solar Cells

2012 ◽  
pp. 48-58
Author(s):  
Laurentiu Fara ◽  
Mihai Razvan Mitroi
Keyword(s):  
Solar Cells ◽  
Quantum Well ◽  
Quantum Efficiency ◽  
Quantum Confinement ◽  
Near Infrared ◽  
Internal Quantum Efficiency ◽  
Infrared Range ◽  
Cell Efficiency ◽  
New Energy ◽  
Valence Bands

In this chapter, the authors present the modelling and simulation of the multi-layered quantum well solar cells as well as the simulated results of this model. The quantum confinement of a semiconductor induces new energy levels, located in the band gap, as well as resonant levels located in the conduction and valence bands. These levels allow supplementary absorption in the visible and near infrared range. The quantum efficiency of the supplementary absorption is calculated within the infinite rectangular quantum well approximation. As the absorption excites carriers in the gap of each layer, even a small absorption significantly increases the photocurrent (by photoassisted tunneling) and, therefore, the cell efficiency. The results of the simulation are presented for the internal quantum efficiency of the transitions between the resonant levels of GaAs, as well as the internal quantum efficiency of the transitions between the confinement levels for GaAs and AlxGa1-xAs. New directions for the research of quantum well solar cells are indicated.

scholarly journals A Highly Robust Silicon Ultraviolet Selective Radiation Sensor Using Differential Spectral Response Method

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2755 ◽  
Author(s):  
Yhang Ricardo Sipauba Carvalho da Silva ◽  
Rihito Kuroda ◽  
Shigetoshi Sugawa
Keyword(s):  
Quantum Efficiency ◽  
Near Infrared ◽  
Background Radiation ◽  
Uv Light ◽  
Internal Quantum Efficiency ◽  
Spectral Response ◽  
Optical Filters ◽  
Nir Light ◽  
Radiation Sensor ◽  
Response Method

This paper presents a silicon ultraviolet radiation sensor with over 90% UV internal quantum efficiency (QE) and high selectivity to the UV waveband without using optical filters. The sensor was developed for applications that require UV measurement under strong background visible and near-infrared (NIR) lights, such as solar UV measurement, UV-C monitoring in greenhouses or automated factories, and so on. The developed sensor is composed of monolithically formed silicon photodiodes with different spectral sensitivities: a highly UV responsive photodiode with internal quantum efficiency (QE) of nearly 100% for UV light, and a lowly UV responsive photodiode with UV internal QE lower than 10%. The photodiodes were optimized to match their visible and NIR light responsivity, and the UV signal is extracted from the background radiation by using the differential spectral response method. With this approach, an internal QE of over 90% for UV light was obtained, with a residual internal QE to non-UV light lower than 20% for 400 nm, 5% for 500 nm, 2% for 600 nm and 0.6% to NIR light. The developed sensor showed no responsivity degradation after exposure towards strong UV light. It was confirmed by the simulation results that the residual responsivity is further suppressed by employing an on-chip band-rejection optical layer consisting of several layers of silicon oxide and silicon nitride films.

Quantum Confinement Modeling and Simulation for Quantum Well Solar Cells

2014 ◽  
pp. 731-741
Author(s):  
Laurentiu Fara ◽  
Mihai Razvan Mitroi
Keyword(s):  
Solar Cells ◽  
Quantum Well ◽  
Quantum Efficiency ◽  
Quantum Confinement ◽  
Near Infrared ◽  
Internal Quantum Efficiency ◽  
Infrared Range ◽  
Cell Efficiency ◽  
New Energy ◽  
Valence Bands

In this chapter, the authors present the modelling and simulation of the multi-layered quantum well solar cells as well as the simulated results of this model. The quantum confinement of a semiconductor induces new energy levels, located in the band gap, as well as resonant levels located in the conduction and valence bands. These levels allow supplementary absorption in the visible and near infrared range. The quantum efficiency of the supplementary absorption is calculated within the infinite rectangular quantum well approximation. As the absorption excites carriers in the gap of each layer, even a small absorption significantly increases the photocurrent (by photoassisted tunneling) and, therefore, the cell efficiency. The results of the simulation are presented for the internal quantum efficiency of the transitions between the resonant levels of GaAs, as well as the internal quantum efficiency of the transitions between the confinement levels for GaAs and AlxGa1-xAs. New directions for the research of quantum well solar cells are indicated.

Measuring the reflectance and the internal quantum efficiency of silicon and InGaAs/InP photodiodes in near infrared range

2008 ◽  
Author(s):  
Ana Luz Muñoz Zurita ◽  
Joaquin Campos Acosta ◽  
Alexandre S. Shcherbakov ◽  
Alicia Pons Aglio
Keyword(s):  
Quantum Efficiency ◽  
Near Infrared ◽  
Internal Quantum Efficiency ◽  
Infrared Range ◽  
Near Infrared Range

scholarly journals Towards efficient near-infrared fluorescent organic light-emitting diodes

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Alessandro Minotto ◽  
Ibrahim Bulut ◽  
Alexandros G. Rapidis ◽  
Giuseppe Carnicella ◽  
Maddalena Patrini ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Near Infrared ◽  
Light Emitting Diodes ◽  
Energy Gap ◽  
Internal Quantum Efficiency ◽  
Organic Light Emitting Diodes ◽  
General Strategy ◽  
Light Emitting ◽  
Organic Light ◽  
Radiative Rate

AbstractThe energy gap law (EG-law) and aggregation quenching are the main limitations to overcome in the design of near-infrared (NIR) organic emitters. Here, we achieve unprecedented results by synergistically addressing both of these limitations. First, we propose porphyrin oligomers with increasing length to attenuate the effects of the EG -law by suppressing the non-radiative rate growth, and to increase the radiative rate via enhancement of the oscillator strength. Second, we design side chains to suppress aggregation quenching. We find that the logarithmic rate of variation in the non-radiative rate vs. EG is suppressed by an order of magnitude with respect to previous studies, and we complement this breakthrough by demonstrating organic light-emitting diodes with an average external quantum efficiency of ~1.1%, which is very promising for a heavy-metal-free 850 nm emitter. We also present a novel quantitative model of the internal quantum efficiency for active layers supporting triplet-to-singlet conversion. These results provide a general strategy for designing high-luminance NIR emitters.

scholarly journals Perspectives on UVC LED: Its Progress and Application

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 196
Author(s):  
Tsung-Chi Hsu ◽  
Yu-Tsai Teng ◽  
Yen-Wei Yeh ◽  
Xiaotong Fan ◽  
Kuo-Hsiung Chu ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Flip Chip ◽  
Layer Structure ◽  
Light Emitting Diode ◽  
Internal Quantum Efficiency ◽  
Reverse Current ◽  
Light Extraction ◽  
Epitaxial Layers ◽  
High Electron ◽  
Recombination Rates

High-quality epitaxial layers are directly related to internal quantum efficiency. The methods used to design such epitaxial layers are reviewed in this article. The ultraviolet C (UVC) light-emitting diode (LED) epitaxial layer structure exhibits electron leakage; therefore, many research groups have proposed the design of blocking layers and carrier transportation to generate high electron–hole recombination rates. This also aids in increasing the internal quantum efficiency. The cap layer, p-GaN, exhibits high absorption in deep UV radiation; thus, a small thickness is usually chosen. Flip chip design is more popular for such devices in the UV band, and the main factors for consideration are light extraction and heat transportation. However, the choice of encapsulation materials is important, because unsuitable encapsulation materials will be degraded by ultraviolet light irradiation. A suitable package design can account for light extraction and heat transportation. Finally, an atomic layer deposition Al2O3 film has been proposed as a mesa passivation layer. It can provide a low reverse current leakage. Moreover, it can help increase the quantum efficiency, enhance the moisture resistance, and improve reliability. UVC LED applications can be used in sterilization, water purification, air purification, and medical and military fields.

Sign in / Sign up

Export Citation Format

Share Document