• TCAD Examples

ledex02.in : UV 4 Multi Quantum Well GaN LED

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

This example demonstrate how the Atlas radiative recombination models can be used to analyze the Electro-Luminous spectrum of an UV LED.

The objective of this example is to get the basic LED characteristics such as the I-V-L curve and EL spectrum. The input decks shows the 8 sections required to make a basic LED input file. These sections create the structure, specify the model combination and biasing, and finally plot the curves.

Mesh Generation

The first section of the input file defines the mesh. The device diameter is 120um, so 1.13e4 [um] is specified on WIDTH parameter of the MESH statement.

Region and Electrode 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 -0.15 for the AlGaN 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.

Doping Profiles

Layers 1, 2 and 3 are P-type with a doping of 1e20 cm-3. Layers 4 to 10 are the multi-quantum well regions and are undoped. Layers 11 and 12 are N-type with a doping of 2e18 cm-3. All doping profiles have a uniform distribution.

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.

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

EXTRACT was used to calculate the the electron and hole concentration as a function of the bias. The I-V-L and EL spectrum are also plotted.

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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