Precise Electrical Characterization of LEDs with Wide-Band Material

The accurate electrical properties of semiconductor GaN based blue Light-Emitting Diodes (LED) with Multiple-Quantum Well (MQW) structure and GaAsP based red LED, were measured by single Capacitance-Voltage (C-V) method and single Current-Voltage (I-V) method at large forward bias. After comparing the experimental results, we found that the apparent capacitance Cp of GaN based blue LED and GaAsP based red LED measured by C-V method display obviously negative value at large forward bias and low frequency, which is in conflict with the well known Shockley's p-n junction theory and model. Besides, the precise Characterization of apparent capacitance Cp and apparent conductance Gp is obtained.

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Photoluminescence and Electroluminescence Characterization of InxGa1-xN/InyGa1-yN Multiple Quantum Well Light Emitting Diodes

Materials Science Forum ◽

10.4028/www.scientific.net/msf.389-393.1493 ◽

2002 ◽

Vol 389-393 ◽

pp. 1493-1496

Author(s):

Peder Bergman ◽

G.R. Pozina ◽

Bo Monemar ◽

Satoshi Kamiyama ◽

Motoaki Iwaya ◽

...

Keyword(s):

Quantum Well ◽

Light Emitting Diodes ◽

Multiple Quantum Well ◽

Multiple Quantum ◽

Light Emitting

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LOW TEMPERATURE ELECTROLUMINESCENCE OF GREEN AND DEEP GREEN GaInN/GaN LIGHT EMITTING DIODES

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156407004187 ◽

2007 ◽

Vol 17 (01) ◽

pp. 25-28 ◽

Cited By ~ 1

Author(s):

Y. Li ◽

W. Zhao ◽

Y. Xia ◽

M. Zhu ◽

J. Senawiratne ◽

...

Keyword(s):

Low Temperature ◽

Light Emitting Diodes ◽

Multiple Quantum Well ◽

Blue Shift ◽

Multiple Quantum ◽

Acceptor Pair ◽

Light Emitting ◽

Current Voltage ◽

Temperature Spectra ◽

Donor Acceptor

Electroluminescence of GaInN/GaN multiple-quantum-well (QW) light-emitting diodes emitting in the green spectral region is analyzed at variable low temperature. Spectra are dominated by QW emission at RT throughout 7.7 K. Below 150 K, donor-acceptor pair recombination appears that must be assigned to residual impurities in either the barriers or the p-layers. The current-voltage behavior reveals shunt paths that carry up to several mA at low bias voltages. Below 20 K those paths are frozen out, but the device still emits predominantly from the QW. The peak energy exhibits a blue shift from RT to 158 K followed by a red shift from 158 K to 7.7 K. The deeper binding energy at low temperatures can hardly be affect by the injection current indicating that saturation of low-density states cannot be responsible for the transition between red and blue shifts.

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Ultraviolet light emitting diodes using non-polar A-plane AlGaN multiple quantum wells

MRS Proceedings ◽

10.1557/proc-0955-i04-08 ◽

2006 ◽

Vol 955 ◽

Author(s):

Ramya Chandrasekaran ◽

Anirban Bhattacharyya ◽

Ryan France ◽

Christos Thomidis ◽

Adrian Williams ◽

...

Keyword(s):

Quantum Wells ◽

Ultraviolet Light ◽

Light Emitting Diodes ◽

Multiple Quantum Well ◽

Multiple Quantum ◽

Light Emitting ◽

Current Voltage ◽

Uv Leds ◽

Ultraviolet Light Emitting Diodes ◽

Electro Luminescence

ABSTRACTIn this paper, we report the growth and fabrication of non-polar A-plane AlGaN multiple quantum well based ultraviolet light emitting diodes (UV-LEDs). The LEDs were grown on R-plane sapphire substrates using molecular beam epitaxy (MBE). The Current-voltage characteristics of the fabricated devices demonstrated rectifying behavior with a series resistance of 38 ohms. An electro-luminescence emission at 338 nm was obtained.

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Electrical Characterization of Polyfluorene-Based Metal-Insulator-Semiconductor Diodes

MRS Proceedings ◽

10.1557/proc-0937-m07-08 ◽

2006 ◽

Vol 937 ◽

Cited By ~ 1

Author(s):

M. Yun ◽

M. Arif ◽

S. Gangopadhyay ◽

S. Guha

Keyword(s):

Layer Structure ◽

Electrical Characterization ◽

Doping Density ◽

Metal Insulator ◽

Metal Insulator Semiconductor ◽

Light Emitting ◽

Unintentional Doping ◽

Current Voltage ◽

Mis Diode

ABSTRACTPolyfluorenes (PFs) have emerged as a promising family of blue polymer light-emitting diodes (PLED) due to their high electroluminescence quantum yield. Metal-insulator-semiconductor (MIS) diodes are the two terminal analogues of thin film transistors sharing the same basic layer structure. We have investigated two different structures based on poly [9,9'-(di 2-ethylhexyl)fluorene] (PF2/6), a MIS diode and a hole-only PLED. The MIS diodes were fabricated with the PF2/6 layer on p+ Si /Al2O3 substrates, and were characterized by means of capacitance-voltage (C-V) measurements as a function of frequency. From C-V measurements, the unintentional doping density is evaluated as ∼5.7×1017 cm−3 at frequencies above 20 kHz. The interface trap density is estimated as ∼7.2×1011 eV−1cm−2 at 10 kHz. Current-voltage measurements of PF2/6-based PLEDs shows a shallow trap space-charge-limited conduction from which the energy of the traps and hole mobilities are estimated.

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New UV Light Emitter Based on AlGaN Heterostructures with Graded Electron and Hole Injectors

MRS Proceedings ◽

10.1557/proc-743-l7.4 ◽

2002 ◽

Vol 743 ◽

Cited By ~ 2

Author(s):

M.A.L. Johnson ◽

J.P. Long ◽

J. F. Schetzina

Keyword(s):

Aluminum Gallium Nitride ◽

Light Emission ◽

Uv Light ◽

Multiple Quantum Well ◽

Forward Bias ◽

Hole Injection ◽

Bandgap Energy ◽

Multiple Quantum ◽

Device Structure ◽

Light Emitting

ABSTRACTNew ultraviolet (UV) light emitting device structures address the problems of small carrier concentrations and large band-offsets in wide bandgap Aluminum Gallium Nitride (AlGaN) heterostructures through the use of graded epilayers for electron and hole injection. For light emission at 280–290 nm, a multiple-quantum-well separate confinement heterostructure (MQWSCH) employs a graded AlGaN structure for the injection of majority carriers from the metal-semiconductor contact layers into the spacecharge region of the pn-junction with a higher bandgap energy. Sample LED mesa devices were fabricated and have shown light emission of 289 nm under a forward bias of 12V (20mA). These results provide a ‘proof-of-concept’ for this new graded device structure which can be employed for the development of both UV-LEDs and laser diodes.

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