scholarly journals Investigation of Forward Tunneling Characteristics of InGaN/GaN Blue Light-Emitting Diodes on Freestanding GaN Detached from a Si Substrate

Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 543 ◽  
Author(s):  
Moonsang Lee ◽  
Hyunkyu Lee ◽  
Keun Song ◽  
Jaekyun Kim
Keyword(s):  
Leakage Current ◽  
Blue Light ◽  
Light Emitting Diodes ◽  
Forward Bias ◽  
Si Substrate ◽  
Temperature Dependent ◽  
Light Emitting ◽  
Current Voltage ◽  
Current Characteristics ◽  
Recombination Current

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.

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

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.

Mechanisms of Forward Current and Reverse Leakage Current in GaN-Based Blue Light Emitting Diodes

2013 ◽  
Vol 380-384 ◽  
pp. 3035-3038 ◽  
Author(s):  
Ren Jian ◽  
Li Sha Li ◽  
Da Wei Yan ◽  
Xiao Feng Gu
Keyword(s):  
Leakage Current ◽  
Blue Light ◽  
Light Emitting Diodes ◽  
Tunneling Current ◽  
Light Emitting ◽  
Reverse Leakage Current ◽  
Tunneling Mechanism ◽  
Forward Current ◽  
Current Voltage ◽  
High Bias

By measuring the current-voltage (I-V) characteristics in the temperature range of 100 K to 300 K, mechanisms of the forward tunneling current and the reverse leakage current of GaN-based blue light emitting diodes are analyzed. For the forward current, both the temperature-independent current slope and an ideality factor larger than 2 are typical features of the defect-assisted tunneling mechanism. For the reverse leakage current, the linear relationship between I and (V+Vbi)1/2 indicates a hopping conduction mechanism at low bias, while the power law I-V relationship suggests that the space charge limited current dominates the reverse leakage current at high bias.

Electrical Measurement of Recombination Lifetime in Blue Light Emitting Diodes

2004 ◽  
Vol 829 ◽  
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.

Cathode effect on current-voltage characteristics of blue light-emitting diodes based on a polyspirofluorene

2008 ◽  
Author(s):  
G. Garcia-Belmonte ◽  
E. M. Barea ◽  
Y. Ayyad-Limonge ◽  
J. M. Montero ◽  
H. J. Bolink ◽  
...  
Keyword(s):  
Blue Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Current Voltage ◽  
Current Voltage Characteristics

scholarly journals Hexagonal Boron Nitride Passivation Layer for Improving the Performance and Reliability of InGaN/GaN Light-Emitting Diodes

2021 ◽  
Vol 11 (19) ◽  
pp. 9321
Author(s):  
Gun Hee Lee ◽  
Tran Viet Cuong ◽  
Dong Kyu Yeo ◽  
Hyunjin Cho ◽  
Beo Deul Ryu ◽  
...  
Keyword(s):  
Leakage Current ◽  
Light Emitting Diodes ◽  
Hexagonal Boron Nitride ◽  
Operating Temperature ◽  
Passivation Layer ◽  
Light Emitting ◽  
Heat Dispersion ◽  
Current Characteristics ◽  
Dispersion Layer ◽  
Low Temperature Process

We introduce a low temperature process for coating InGaN/GaN light-emitting diodes (LEDs) with h-BN as a passivation layer. The effect of h-BN on device performance and reliability is investigated. At −5 V, the leakage current of the h-BN passivated LED was -1.15 x 10−9 A, which was one order lower than the reference LED’s leakage current of −1.09 × 10−8 A. The h-BN layer minimizes the leakage current characteristics and operating temperature by acting as a passivation and heat dispersion layer. With a reduced working temperature of 33 from 45 °C, the LED lifetime was extended 2.5 times following h-BN passivation. According to our findings, h-BN passivation significantly improves LED reliability.

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