Temperature-dependent ac
 current-voltage-capacitance characteristics of GaN-based light-emitting diodes under high forward bias

We report forward tunneling characteristics of InGaN/GaN blue light emitting diodes (LEDs) on freestanding GaN detached from a Si substrate using temperature-dependent current–voltage (T-I-V) measurements. T-I-V analysis revealed that the conduction mechanism of InGaN/GaN LEDs using the homoepitaxial substrate can be distinguished by tunneling, diffusion and recombination current, and series resistance regimes. Their improved crystal quality, inherited from the nature of homoepitaxy, resulted in suppression of forward leakage current. It was also found that the tunneling via heavy holes in InGaN/GaN LEDs using the homoepitaxial substrate can be the main transport mechanism under low forward bias, consequentially leading to the improved forward leakage current characteristics.

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Electrical and Optical Properties of InGaN/AlGaN Double Heterostructure Blue Light-Emitting Diodes

MRS Proceedings ◽

10.1557/proc-468-469 ◽

1997 ◽

Vol 468 ◽

Author(s):

K. Yang ◽

H. T. Shi ◽

B. Shen ◽

R. Zhang ◽

Z. Z. Chen ◽

...

Keyword(s):

Blue Light ◽

Carrier Transport ◽

Light Emitting Diodes ◽

Forward Bias ◽

Optical Emission ◽

Emission Peak ◽

Light Emitting ◽

Double Heterostructure ◽

Current Voltage ◽

Carrier Tunneling

ABSTRACTIn this paper, we studied the electrical and optical characteristics of Nichia double heterostructure blue light-emitting diodes, with In0.06Ga0.94N:Zn, Si active layer, at 77 and 300 K. Measurement of the forward bias current-voltage behavior of the device demonstrates a departure from the Shockley model of p-n diodes, and it is observed that the dominant mechanism of carrier transport across the junction is associated with carrier tunneling. Electroluminescence experiments of the devices were performed. We obtained an emission peak located at 2.80 eV, and a relatively weaker short-wavelength peak of 3.2 eV. A significant blue shifts of the optical emission peak which is consistent with the tunneling character of electrical characteristics was observed. Furthermore, we studied the properties of electroluminescence under various pulsed currents, and a degradation in I-V characteristics and a low resistance ohmic short were observed.

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Temperature-Dependent Internal Quantum Efficiency of Blue High-Brightness Light-Emitting Diodes

IEEE Journal of Quantum Electronics ◽

10.1109/jqe.2014.2359958 ◽

2014 ◽

Vol 50 (11) ◽

pp. 911-920 ◽

Cited By ~ 60

Author(s):

Ilya E. Titkov ◽

Sergey Yu. Karpov ◽

Amit Yadav ◽

Vera L. Zerova ◽

Modestas Zulonas ◽

...

Keyword(s):

Quantum Efficiency ◽

Light Emitting Diodes ◽

Internal Quantum Efficiency ◽

Temperature Dependent ◽

High Brightness ◽

Light Emitting

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Electrical Measurement of Recombination Lifetime in Blue Light Emitting Diodes

MRS Proceedings ◽

10.1557/proc-829-b2.11 ◽

2004 ◽

Vol 829 ◽

Cited By ~ 1

Author(s):

M. A. Awaah ◽

R. Nana ◽

K. Das

Keyword(s):

Blue Light ◽

Light Emitting Diodes ◽

Deep Level ◽

Electrical Measurement ◽

High Concentration ◽

Recombination Lifetime ◽

Light Emitting ◽

Radiative Processes ◽

Current Voltage ◽

Capacitance Voltage

ABSTRACTA recombination lifetime of approximately 25 ns was extracted from measured reverse recovery storage times in AlGaN/GaN/AlGaN double heterojunction blue light emitting diodes. This experimentally determined lifetime is expected to arise from a combination of radiative and non-radiative processes occurring in the diodes. The non-radiative processes are likely to be due the presence of a high concentration deep-states as identified from the current-voltage and capacitance-voltage measurements. Current-voltage characteristics of these diodes were highly non-ideal as indicated by high values of the ideality factor ranging from 3.0 – 7.0. Logarithmic plots of the forward characteristics indicated a space-charge-limited-current (SCLC) conduction in presence of a high density of “deep-level states” in the active region of the diodes. An analysis of these characteristics yielded an approximate density of these deep-level states as 2 × 1017/cm3. The density of deep-states extracted from capacitance-voltage measurements were in good agreement with that obtained from current-voltage measurements.

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