Status of Growth of Group III-Nitride Heterostructures for Deep Ultraviolet Light-Emitting Diodes

Ding, Kai; Avrutin, Vitaliy; Özgür, Ü.; Morkoç̌, H.

doi:10.20944/preprints201709.0013.v1

Cited by 4 publications

(3 citation statements)

References 98 publications

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“…The structural aspect of innovative diodes is generally achieved by adding a new structure or improving the original structure, which makes the diode gain higher in various performance aspects. For example, in 2022, a diode with an improved shape of the original electron barrier layer (EBL) was compared to be more effective in suppressing electron leakage when the structure was an inverted trapezoidal rectangle [12]. In terms of innovative new structures, a vertical GaN-based trapezoidal diode with a composite dielectric layer was proposed to improve the voltage resistance of the device, and in 2021, a scientific research team further optimized this by adjusting the width of the dielectric layer, the size of the trapezoidal bottom angle, and other parameters to find a better structure, which effectively improves the voltage resistance of the device [13].…”

Section: Diode Optimizationmentioning

confidence: 99%

Current Status, Development, And Application of Optimization Methods for Analog Circuits

Liu

2024

HSET

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The optimization of analog circuits has always relied on the experience and intuition of engineers to find suitable parameters to meet the requirements of the circuit, which is time-consuming and costly. This paper outlines and analyzes the optimization methods for analog circuits in recent years, and draws some summaries that can be used as references for subsequent optimization circuits. The optimization of analog circuits is mainly divided into the optimization of the performance of the hardware in the circuit and the optimization of the circuit structure. Hardware optimization, this paper mainly focuses on the optimization of diodes, transistors, field effect tubes and operational amplifiers, the four main hardware optimizations, from the material, structure, production process and other aspects of the analysis. For the optimization of circuit structure, this paper mainly analyzes from the aspects of algorithms, mathematical models, and the use of integrated methods. The significance of these optimization methods and the outstanding advantages and main application directions of different methods are further explained. The search for optimization methods can reduce the high time cost of analog circuit optimization that is purely dependent on experience and intuition, and is significant in increasing efficiency.

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Section: Diode Optimizationmentioning

confidence: 99%

Current Status, Development, And Application of Optimization Methods for Analog Circuits

Liu

2024

HSET

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“…Wu and Jeng presented a simple behavioral model with experimentally extracted parameters for packaged cascode gallium nitride (GaN) field-effect transistors (FETs) [18]. K. Ding, V. Avrutin, Ü. Özgür, and H. Morkoç reviewed the recent progress in growth aspects of group III-nitride heterostructures for deep ultraviolet (DUV) light-emitting diodes (LEDs), with particular emphasis on the growth approaches for attaining high-quality AlN and high Al-molar fraction AlGaN [19]. Finally, Han-Youl Ryu theoretically evaluated the light extraction efficiency (LEE) of GaN-based nanorod blue light-emitting diode (LED) structures using finite-difference time-domain (FDTD) simulations [20].…”

Section: Current Perspectives In the Applications Of Nanostructured Ganmentioning

confidence: 99%

Advances in GaN Crystals and Their Applications

2018

Crystals

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This special issue looks at the potential applications of GaN-based crystals in both fields of nano-electronics and optoelectronics. The contents will focus on the fabrication and characterization of GaN-based thin films and nanostructures. It consists of six papers, indicating the current developments in GaN-related technology for high-efficiency sustainable electronic and optoelectronic devices, which include the role of the AlN layer in high-quality AlGaN/GaN heterostructures for advanced high-mobility electronic applications and simulation of GaN-based nanorod high-efficiency light-emitting diodes for optoelectronic applications. From the results, one can learn the information and experience available in the advanced fabrication of nanostructured GaN-based crystals for nano-electronic and optoelectronic devices.Keywords: GaN; AlN; InN; AlGaN; InGaN; MOSFET; LED Applications of GaN-Based CompoundsReviewing the application of semiconductor compounds, it stemmed from the replacement of vacuum tube by transistors in electronics [1,2]. The first "point-contact transistor" was invented by J. Bardeen and W. H. Brattain with "three-electrode elements" utilizing semiconductor materials, p-type, and n-type germaniums [1]. As the germanium crystal was substituted by silicon crystal to make a p-n-p bipolar junction transistor [3] or metal-oxide-semiconductor field effect transistor (MOSFET) [4], the electronic property of transistor was tremendously enhanced and the silicon-based electronic industry was then established. However, the VI-elements (i.e., Ge, Si) are basically indirect band structure, which is not suitable for the application of photo-electronic devices. When the IV-elements (Si or Ge) are replaced by GaAs-based III-V compounds, the electron mobility of MOSFET can be significantly increased [5] and quantum effects (e.g., normal and fractional quantum Hall effects) can be clearly detected [6,7]. In addition to the high-speed transistor applications, the direct band structures of GaAs-based III-V compounds extended the semiconductor materials to photo-electronic applications, in which the IV-elements (Si or Ge) are exclusive due to the indirect band structure. In such a way, the GaAs-based heterostructures were successfully utilized in the information and communication technology [8]. Moreover, many opto-electronic devices were invented with GaAs-compounds such as light-emitting diodes (LED) and laser diodes (LD). In other words, GaAs-based III-V compounds can be designed to apply in both electronic and opto-electronic devices. However, the light-sources made of GaAs-based compounds (group III-arsenides) were limited to the emitting photon wavelength greater than 760 nm (red light) due to the bandgap energy (i.e., E g = 1.424 eV of GaAs). On the other hand, the direct bandgap energy of group III-nitrides can cover the range from 0.7 eV (InN), 3.4 eV (GaN), to 6.2 eV (AlN). Therefore, the III-nitrides can offer a simple material system, replacing III-arsenides to integrate both electronic and opto-e...

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“…Recently, a world record external quantum efficiency (EQE) of 20% at 275 nm has been achieved by enhancing the light extraction efficiency [6]. However, the EQE of DUV LEDs is still far from satisfactory (less than 10% in most cases), mainly due to non-radiative recombination, severe electron leakage and insufficient hole injection issues [7]. Various efforts have been made to improve the optical and electrical performance of DUV LEDs from the aspect of epitaxial growth of Ⅲ-nitride compounds [8]- [10].…”

Section: Introductionmentioning

confidence: 99%

Sheet Charge Engineering Towards an Efficient Hole Injection in 290 nm Deep Ultraviolet Light-Emitting Diodes

Liu

Zhou

et al. 2021

IEEE Photonics J.

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The hole injection efficiency is one of the bottlenecks that restricts the external quantum efficiency (EQE) and optical power of AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs). The polarization-induced positive sheet charges at the last quantum barrier (LQB)/electron blocking layer (EBL) interface reflect the holes back to the p-type layer and weaken the hole injection capability into the active region. In this work, we designed and incorporated a polarization-engineered AlxGa1-xN/AlyGa1-yN superlattice layer at the LQB/EBL interface. The positive sheet charges at the LQB/EBL interface can be inverted into negative charges with optimal Al compositions in the AlxGa1-xN/AlyGa1-yN superlattice layer. The electron confinement and hole injection efficiency can also be improved through increasing the effective barrier height for electrons and decreasing the effective barrier height for holes, resulting in an enhanced optical power by 29.4% and alleviated efficiency droop by 78.4% for the proposed device with an Al0.67Ga0.33N/Al0.7Ga0.3N superlattice insertion layer. The sheet charge engineering method by polarization provides an alternative approach to boost the hole injection efficiency towards an enhanced device performance for DUV LEDs.

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Status of Growth of Group III-Nitride Heterostructures for Deep Ultraviolet Light-Emitting Diodes

Cited by 4 publications

References 98 publications

Current Status, Development, And Application of Optimization Methods for Analog Circuits

Current Status, Development, And Application of Optimization Methods for Analog Circuits

Advances in GaN Crystals and Their Applications

Sheet Charge Engineering Towards an Efficient Hole Injection in 290 nm Deep Ultraviolet Light-Emitting Diodes

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