Characterization and simulation of 280 nm UV-LED degradation

Su, Mengwei; Zhu, Xinglin; Guo, Qi; Chen, Zhiqiang; Deng, Shaodong; Chen, Ziqian; Wang, Yukun; Deng, Jixian; Sun, Wenhong

doi:10.1063/5.0040008

Cited by 13 publications

(10 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the past two decades, researchers have made a great deal of efforts to improve the EQE and WPE of AlGaN‐based UV LEDs, which have made great progress. [ 5–7,11,17–19,30,33–91 ] Figures and show the EQE and WPE for UV LEDs of different emission wavelengths by various research groups (till dated 2021/8/30) respectively. As shown in Figure 2, we can see that the EQE gradually decreased while the emission wavelength reduced from 400 to 200 nm.…”

Section: Overview Of Algan‐based Uv Ledsmentioning

confidence: 99%

“…External quantum efficiency (EQE) of different peak wavelengths by various research groups. [ 5–7,11,17–19,30,33–91 ] The corresponding full name of mentioned abbreviations are listed as following: Chinese Academy of Sciences (CAS), Ferdinand‐Braun‐Institut, Berlin (FBH‐Berlin), Hebei University of Technology (HEBUT), Huazhong University of Science and Technology (HUST), Fraunhofer Institute for Applied Solid State Physics (IAF), National Chiao Tung University (NCTU), Nippon Telegraph and Telephone Corporation (NTT), National Institute of Information and Communications Technology (NICT), Ohio State University (OSU), Palo Alto Research Center (PARC), Sensor Electronic Technology, Inc (SETi), Technische Universität Berlin (TU Berlin), University of Wisconsin–Madison (UM‐Madison), University of South Carolina (USC), University of Science and Technology of China (USTC).…”

Section: Overview Of Algan‐based Uv Ledsmentioning

confidence: 99%

See 1 more Smart Citation

Recent Advances in Packaging Technologies of AlGaN‐Based Deep Ultraviolet Light‐Emitting Diodes

Liang

Sun

2022

Adv Materials Technologies

Self Cite

View full text Add to dashboard Cite

AlGaN‐based deep ultraviolet light‐emitting diodes (UV LEDs) have gained rapidly growing attention due to their wide applications in water purification, air disinfection, and sensing as well as optical communication. Moreover, deep UV radiation has been verified as one of effective way to inactivate COVID‐19. However, although numerous efforts have been made in deep UV LED chips, the reported highest external quantum efficiency (EQE) of them is 20.3%, which is far lower than that of visible LEDs. The EQE of commercial packaged AlGaN‐based deep UV LEDs is usually lower than 5%, which will cause serious reliability problems as well. Therefore, it is very urgent to improve EQE and reliability of the devices from packaging level. In this review, a systematical summarization about the packaging technologies of AlGaN‐based deep UV LEDs has been analyzed and future prospects have been made as well. Firstly, this work provides a brief overview of the devices and analyzes why the packaging level reduces EQE and reliability in theory. Then, systematically reviews the recent advances in packaging technologies and deep UV micro‐LEDs. Finally, conclusions and outlooks are given as well. This review is of great significance for promoting the development of the packaging technologies for AlGaN‐based deep UV LEDs.

show abstract

Section: Overview Of Algan‐based Uv Ledsmentioning

confidence: 99%

Section: Overview Of Algan‐based Uv Ledsmentioning

confidence: 99%

Recent Advances in Packaging Technologies of AlGaN‐Based Deep Ultraviolet Light‐Emitting Diodes

Liang

Sun

2022

Adv Materials Technologies

Self Cite

View full text Add to dashboard Cite

show abstract

“…Our group figured out the CV measurements in a frequency range of 200 Hz–2 MHz to verify the subordination of the capacitance characteristics [ 73 ]. The capacitance–frequency is illustrated in Figure 18 .…”

Section: Degradation Effects On C–v Characteristicsmentioning

confidence: 99%

Reliability Analysis of AlGaN-Based Deep UV-LEDs

2022

Self Cite

View full text Add to dashboard Cite

The current pandemic crisis caused by SARS-CoV-2 has also pushed researchers to work on LEDs, especially in the range of 220–240 nm, for the purpose of disinfecting the environment, but the efficiency of such deep UV-LEDs is highly demanding for mass adoption. Over the last two decades, several research groups have worked out that the optical power of GaN-based LEDs significantly decreases during operation, and with the passage of time, many mechanisms responsible for the degradation of such devices start playing their roles. Only a few attempts, to explore the reliability of these LEDs, have been presented so far which provide very little information on the output power degradation of these LEDs with the passage of time. Therefore, the aim of this review is to summarize the degradation factors of AlGaN-based near UV-LEDs emitting in the range of 200–350 nm by means of combined optical and electrical characterization so that work groups may have an idea of the issues raised to date and to achieve a wavelength range needed for disinfecting the environment from SARS-CoV-2. The performance of devices submitted to different stress conditions has been reviewed for the reliability of AlGaN-based UV-LEDs based on the work of different research groups so far, according to our knowledge. In particular, we review: (1) fabrication strategies to improve the efficiency of UV-LEDs; (2) the intensity of variation under constant current stress for different durations; (3) creation of the defects that cause the degradation of LED performance; (4) effect of degradation on C-V characteristics of such LEDs; (5) I-V behavior variation under stress; (6) different structural schemes to enhance the reliability of LEDs; (7) reliability of LEDs ranging from 220–240 nm; and (8) degradation measurement strategies. Finally, concluding remarks for future research to enhance the reliability of near UV-LEDs is presented. This draft presents a comprehensive review for industry and academic research on the physical properties of an AlGaN near UV-LEDs that are affected by aging to help LED manufacturers and end users to construct and utilize such LEDs effectively and provide the community a better life standard.

show abstract

“…Compared with conventional mercury gas-discharge lamps, the exceptional characteristics of UV-LED devices, there are still technological di culties, including the understanding of the degradation mechanisms, which limit the lifetime reliability and rapid market penetration of UV-C LEDs. Since the physical mechanisms responsible for degradation of UV-LEDs have not been completely identi ed, numerous researches have been conducted on the reliability analysis of UV-LEDs in recent years [6][7][8]. It is known that the threading dislocations densities (TDD) and poor ohmic contacts with high Al-content AlGaN layers lead to a mass of Joule heating and non-radiative recombination heating in the device during operation which accelerates degradation [9,10].…”

Section: Introductionmentioning

confidence: 99%

Degradation analysis with characteristics and simulations of 265 nm UV-C LED

Zhu

Chen

et al. 2021

J Mater Sci: Mater Electron

Self Cite

View full text Add to dashboard Cite

We report the degradation study on AlGaN-based 265 nm ultraviolet light emitting diodes (UV-LEDs) under a series of constant current stress. The failure mechanisms were investigated systematically by measuring the optical and electrical characteristics of the LEDs before and after aging. The variation of carrier concentration in the active region was analyzed by capacitance-voltage. Combining the extracted apparent charge distribution pro les with the simulation results of the devices before and after the stress, we found that the change of carrier concentration in the multiple quantum wells was related to the donor diffusion on the n-side. On the p-side, both the acceptor concentration of electron blocking layer (EBL) and the defects in p-GaN contact layer were also found to be under constant change. The reduction of the EBL doping concentration has contributed to an increase of the diode depletion width during the stress. The changes in the LEDs before and after stressing indicate a compensating effect occurred in the p-type EBL close to the quantum wells, which leads to the degradation of the optical power of the 265 nm UV-LEDs.

show abstract

Characterization and simulation of 280 nm UV-LED degradation

Cited by 13 publications

References 29 publications

Recent Advances in Packaging Technologies of AlGaN‐Based Deep Ultraviolet Light‐Emitting Diodes

Recent Advances in Packaging Technologies of AlGaN‐Based Deep Ultraviolet Light‐Emitting Diodes

Reliability Analysis of AlGaN-Based Deep UV-LEDs

Degradation analysis with characteristics and simulations of 265 nm UV-C LED

Contact Info

Product

Resources

About