Design of electron blocking layers for improving internal quantum efficiency of InGaN/AlGaN-based ultraviolet light-emitting diodes

Park, Tae Hoon; Kim, Tae Geun

doi:10.1007/s00339-015-9345-3

Cited by 7 publications

(3 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular, a high EQE of 7.6% was measured, thanks to the effectiveness of the carrier transport manipulation performed by this type of band engineering. Additionally, other types of novel EBL in the form of graded AlGaN structures were demonstrated in [73,79]. All the simulated and experimental results reveal that this type of graded AlGaN EBL can facilitate much higher hole injection efficiencies with reduced energy losses by lowering the effective hole barrier height and screening the strongly polarizing electric fields.…”

Section: A P-ebl In the Form Of A Graded Algan Structurementioning

confidence: 95%

“…To simultaneously achieve efficient current injection and sufficient carrier confinement in AlGaN UV light emitters, compositionally graded AlGaN quantum structures (QWs [66][67][68][69][70], QBs [71][72][73][74], a LQB [75,76], and p-EBLs [77][78][79]) have been tentatively investigated and employed. Such structures can tailor the polarization fields, alleviate band bending, and consequently either increase the electron barrier height or decrease the hole barrier height, to effectively control the carrier transport, confinement, and recombination process.…”

Section: Manipulation Of Carrier Transport Via Energy Band Engineeringmentioning

confidence: 99%

See 1 more Smart Citation

Compositionally graded III-nitride alloys: building blocks for efficient ultraviolet optoelectronics and power electronics

Zhang¹,

Huang²,

Song³

et al. 2021

Rep. Prog. Phys.

122

View full text Add to dashboard Cite

Wide bandgap aluminum gallium nitride (AlGaN) semiconductor alloys have established themselves as the key materials for building ultraviolet (UV) optoelectronic and power electronic devices. However, further improvements to device performance are lagging, largely due to the difficulties in precisely controlling carrier behavior, both carrier generation and carrier transport, within AlGaN-based devices. Fortunately, it has been discovered that instead of using AlGaN layers with fixed Al compositions, by grading the Al composition along the growth direction, it is possible to (1) generate high-density electrons and holes via polarization-induced doping; (2) manipulate carrier transport behavior via energy band modulation, also known as ‘band engineering’. Consequently, such compositionally graded AlGaN alloys have attracted extensive interest as promising building blocks for efficient AlGaN-based UV light emitters and power electronic devices. In this review, we focus on the unique physical properties of graded AlGaN alloys and highlight the key roles that such graded structures play in device exploration. Firstly, we elaborate on the underlying mechanisms of efficient carrier generation and transport manipulation enabled by graded AlGaN alloys. Thereafter, we comprehensively summarize and discuss the recent progress in UV light emitters and power electronic devices incorporating graded AlGaN structures. Finally, we outline the prospects associated with the implementation of graded AlGaN alloys in the pursuit of high-performance optoelectronic and power electronic devices.

show abstract

Section: A P-ebl In the Form Of A Graded Algan Structurementioning

confidence: 95%

Section: Manipulation Of Carrier Transport Via Energy Band Engineeringmentioning

confidence: 99%

Compositionally graded III-nitride alloys: building blocks for efficient ultraviolet optoelectronics and power electronics

Zhang¹,

Huang²,

Song³

et al. 2021

Rep. Prog. Phys.

122

View full text Add to dashboard Cite

show abstract

“…Moreover, the LEE of NUV LEDs is lower than that of blue LEDs owing to self-absorption in the top p-GaN contact layer [9]. Several research groups have attempted to increase the IQE of NUV LEDs by employing AlGaN quantum barriers (QBs) that replace the conventional GaN QBs and AlGaN electron blocking layer (EBL) [13,14]. Even though the efficiency of NUV LEDs has been improved via AlGaN QBs and EBL, the benefit is less than expected.…”

Section: Introductionmentioning

confidence: 99%

Improved performance of InGaN/GaN Near-UV light-emitting diodes with staircase hole injector

Kim

et al. 2021

Eng. Res. Express

View full text Add to dashboard Cite

We report the enhanced performance of near-ultraviolet (NUV) InGaN/GaN multiple quantum-well (MQW) light-emitting diodes (LEDs) with a staircase hole injector (SHI). Simulation results indicate that the internal electrostatic field in the QW of the LED-SHI is decreased owing to the reduced sheet charge density at the interface between QW and quantum barrier (QB) caused by the smaller In content difference. Additionally, the SHI structure in the QBs suppresses the ballistic or quasi-ballistic hole transport, thus enhancing efficient hole injection into the QWs. The radiative output power of an LED-SHI is increased by 25.3% at 300 mA over that of conventional LEDs with GaN QBs. The droop of internal quantum efficiency (IQE) an LED-SHI at 300 A·cm−1 is 6.1%, while the LED with GaN QBs has an IQE droop of 17.7%. The reduced IQE droop and increased radiative output power in the LED-SHI is attributed to the reduced hole overflow, increased hole injection into the MQW and the decreased electrostatic field in the MQWs. The results show that the SHI structure in the LED is promising for improved performance in high-power GaN-based NUV LEDs.

show abstract

White-light emission from AlN dendrites

Shen

Zhang

Song

et al. 2016

J Mater Sci: Mater Electron

View full text Add to dashboard Cite

Design of electron blocking layers for improving internal quantum efficiency of InGaN/AlGaN-based ultraviolet light-emitting diodes

Cited by 7 publications

References 24 publications

Compositionally graded III-nitride alloys: building blocks for efficient ultraviolet optoelectronics and power electronics

Compositionally graded III-nitride alloys: building blocks for efficient ultraviolet optoelectronics and power electronics

Improved performance of InGaN/GaN Near-UV light-emitting diodes with staircase hole injector

White-light emission from AlN dendrites

Contact Info

Product

Resources

About