Nonradiative Recombination, Carrier Localization, and Emission Efficiency of AlGaN Epilayers with Different Al Content

Mickevičius, J.; Podlipskas, Žydrūnas; Aleksiejūnas, R.; Kadys, A.; Jurkevičius, Jonas; Тамулайтис, Г.; Shur, M. S.; Shatalov, M.; Yang, Jinwei; Gaška, R.

doi:10.1007/s11664-015-4132-7

Cited by 6 publications

(3 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the droop-effect, an increasing injection current leads to significant drop off in the emission efficiency of blue LEDs with indium gallium nitride (InGaN) MQW active layers [ 18 , 19 , 20 ]. The mechanisms of the efficiency droop in InGaN LEDs have been studied extensively, where carrier delocalization [ 21 , 22 , 23 ] and electron leakage [ 18 , 24 ] are proposed to be key reasons, while the most recent reports mainly pointing to Auger recombination as the main culprit [ 25 , 26 , 27 , 28 ]. Secondly, particularly in the modern high quantum efficiency LEDs, the efficiency droop limitations, current crowding and resistive loss become the most severe bottlenecks for high output power devices, confining their optimal high-efficiency performance at current densities well below 100 A/cm

[ 29 , 30 , 31 , 32 , 33 , 34 ].…”

Section: Introductionmentioning

confidence: 99%

Diffusion-Driven Charge Transport in Light Emitting Devices

et al. 2017

View full text Add to dashboard Cite

Almost all modern inorganic light-emitting diode (LED) designs are based on double heterojunctions (DHJs) whose structure and current injection principle have remained essentially unchanged for decades. Although highly efficient devices based on the DHJ design have been developed and commercialized for energy-efficient general lighting, the conventional DHJ design requires burying the active region (AR) inside a pn-junction. This has hindered the development of emitters utilizing nanostructured ARs located close to device surfaces such as nanowires or surface quantum wells. Modern DHJ III-N LEDs also exhibit resistive losses that arise from the DHJ device geometry. The recently introduced diffusion-driven charge transport (DDCT) emitter design offers a novel way to transport charge carriers to unconventionally placed ARs. In a DDCT device, the AR is located apart from the pn-junction and the charge carriers are injected into the AR by bipolar diffusion. This device design allows the integration of surface ARs to semiconductor LEDs and offers a promising method to reduce resistive losses in high power devices. In this work, we present a review of the recent progress in gallium nitride (GaN) based DDCT devices, and an outlook of potential DDCT has for opto- and microelectronics.

show abstract

[ 29 , 30 , 31 , 32 , 33 , 34 ].…”

Section: Introductionmentioning

confidence: 99%

Diffusion-Driven Charge Transport in Light Emitting Devices

et al. 2017

View full text Add to dashboard Cite

show abstract

“…In the droop-effect an increasing injection current leads to significant drop off in the emission efficiency of blue LEDs with indium gallium nitride (InGaN) MQW active layers [18][19][20]. The mechanisms of the efficiency droop in InGaN LEDs have been studied extensively, where carrier delocalization [21][22][23] and electron leakage [18,24] are proposed to be key reasons, while the most recent reports mainly pointing to Auger recombination as the main culprit [25][26][27][28]. Secondly, particularly in the modern high quantum efficiency LEDs, the efficiency droop limitations, current crowding and resistive loss become the most severe bottlenecks for high output power devices, confining their optimal high-efficiency performance at current densities well below 100 A/cm 2 [29][30][31][32][33][34].…”

Section: Introductionmentioning

confidence: 99%

Diffusion-Driven Charge Transport in Light Emitting Devices

Kim¹,

Kivisaari²,

Oksanen³

et al. 2017

Preprint

View full text Add to dashboard Cite

Almost all modern inorganic light-emitting diode (LED) designs are based on double heterojunctions (DHJs) whose structure and current injection principle have remained essentially unchanged for decades. Although highly efficient devices based on the DHJ design have been developed and commercialized for energy-efficient general lighting, the conventional DHJ design requires burying the active region (AR) inside a pn-junction. This has hindered the development of emitters utilizing nanostructured ARs located close to device surfaces such as nanowires or surface quantum wells. Modern DHJ III-N LEDs also exhibit resistive losses which arise from the DHJ device geometry. The recently introduced diffusion-driven charge transport (DDCT) emitter design offers a novel way to transport charge carriers to unconventionally placed ARs. In a DDCT device, the AR is located apart from the pn-junction and the charge carriers are injected into the AR by bipolar diffusion. This device design allows the integration of surface ARs to semiconductor LEDs and offers a promising method to reduce resistive losses in high power devices. In this work, we present a review of the recent progress in gallium nitride (GaN) based DDCT devices, and an outlook of potential DDCT has for opto-and microelectronics.

show abstract

“…In addition, the AlGaN-based active region with wider bandgap has lower minority carrier diffusion length 31) in comparison with InGaN/GaN active regions due to heavier hole effective mass and fast recombination rate. 32) The reduced bulk minority carrier diffusion length suggests that carriers are less likely to reach sidewalls so that AlGaN material might be more tolerant of the surface nonradiative recombination caused by the sidewall damage. There are negligible differences in the peak wavelength and FWHM (full-width-at-halfmaximum) between LEDs with different mesa sizes, indicating no major difference in electrical fields within the active region or thermal effect.…”

mentioning

confidence: 99%

Size dependent characteristics of AlGaN-based deep ultraviolet micro-light-emitting-diodes

Yao

et al. 2022

Appl. Phys. Express

View full text Add to dashboard Cite

AlGaN-based deep ultraviolet (DUV) micro-light-emitting diodes (µLEDs) with emission wavelengths between 277nm and 304nm with mesa dimensions down to 20μm were fabricated. Their size-dependent electrical and optical characteristics were analyzed. At 20 A/cm2, the external quantum efficiency (EQE) increased from 2.0% to 2.3% mainly due to the improved light extraction efficiency; the forward voltage was 7.6V in 20µm sized µLEDs in comparison to 9.1V in 300µm LEDs due to better current spreading in the smaller devices. The peak EQEs of the 20μm µLEDs were 2.5% and 4.0% for 277nm and 304nm, among the highest reported for DUV µLEDs.

show abstract

Nonradiative Recombination, Carrier Localization, and Emission Efficiency of AlGaN Epilayers with Different Al Content

Cited by 6 publications

References 27 publications

Diffusion-Driven Charge Transport in Light Emitting Devices

Diffusion-Driven Charge Transport in Light Emitting Devices

Diffusion-Driven Charge Transport in Light Emitting Devices

Size dependent characteristics of AlGaN-based deep ultraviolet micro-light-emitting-diodes

Contact Info

Product

Resources

About