• TCAD Examples

ledex03.in : Blue Single Quantum Well GaN LED

Requires: Blaze/Quantum/LED/DevEdit Minimum Versions: Atlas 5.28.1.R

This example demonstrates how the Atlas radiative recombination models can be used to analyze the Electro-Luminous spectrum for a BLUE LED.

The objective of this example is to get the basic LED characteristics such as the I-V-L curve and EL spectrum. DEVEDIT was used to create the structure. In DEVEDIT, x-direction was scaled down to 1/100, and in Atlas the structure was scaled up to original structure size to 100 times in x-direction.

Structure Generation

DEVEDIT is used to define the LED structure. Atlas then scales the x dimension by 100. The device size is 350*350 um^2, so 477 [um] is used to set the exact Anode Area by specifying WIDTH=477.

Region Specification

To model the effects of strain and the piezo effect, the CALC.STRAIN , POLARIZATION and POLAR.SCALE parameters of the REGION statement can be used. POLAR.SCALE is set to 1.0 for the InGaN materials. This parameter combination will be result in an interface charge of ~1e13 cm-2, depending on the mole fraction of the well/barrier Layer.

To get the EL spectrum, the parameter QWELL and LED should be specified on the quantum active layer region.

The ANODE and CATHODE contacts are defined on the top and bottom of the device.

Material and Models

There are three parts to this section. The first specifies the MATERIAL statement parameters for the recombination and linewidth broadening factor, as well as enabling incomplete ionization. The second part specifies the MODELS statement for the GaN system. The other MODELS statement defines the Gain and EL spectrum models for the SQW region. The CHUANG and SPONTANEOUS are specified along with LORENTZ for linewidth broadening. The third part defines the mobility. Finally, the refractive index was difined with ADACHI model and the Nickel metal given the refractive index of air so that it will be ignored in the reverse raytrace.

Bias Ramp and Save Spectrum

To obtain the EL spectrum, the SPECTRUM parameter and wavelength range LMIN , LMAX and NSAMP are specified on the SAVE statement.

Plotting Curves

To store the I-V-L and EL spectrum and the angluar power distribution, the SAVE statement was used. The MIR.BOTTOM parameter was used to define of the bottom mirror.

To load and run this example, select the Load button in DeckBuild > Examples. This will copy the input file and any support files to your current working directory. Select the Run button in DeckBuild to execute the example.

Additional Info:

Input Files
Output Results
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