How to Optimize Solar Cells Using Ansys Lumerical

Hi everybody, thank you for joining this webinar. My name is Majid Ibn Ali Haidari. I'm the Technical Manager of Photonics at the Ozen Engineering. Today I want to discuss how to optimize solar cells using Ansys Lumerical.

Ozen Engineering is expert in simulation of optics and photonics, structural, thermal, fluid and electromagnetic fields. We offer ANSYS software consulting, training, mentoring and technical support.

The outline of my talk is as follows: 1. Introduction to ANSYS software and its numerical capabilities for solar cell simulation 2. Simulation methodology and workflow 3. Optical simulation: defining material models, source boundary, and setting up the boundary 4. Numerical demo of optical simulation 5. Electronic simulation: defining doping, temperature, and multi quantum well 6. Numerical demo of electronic simulation 7. Example of numerical simulation Lumerical has different packages, including solvers for component level and circuit level.

In this webinar, we will focus on component level, which includes solvers for FTTD mode, FIM, charge, heat, and multi quantum well.

These solvers are useful for simulating light propagation, calculating transmission, absorption, scattering, dispersion parameters, and simulating bulk charge transport in semiconductor devices. Solar cells are a good example of a structure that includes all of these solvers.

To simulate a solar cell, we need to use FTTD heat charge and multi quantum solvers in a 3D CAD environment capable of handling complex geometry. We can define experimental material or use Lumerical library material with optical and electrical characteristics.

The physics behind FTTD involves solving the Maxwell equation for broadband and obtaining results in one single simulation. The charge solver solves drift diffusion and poison equations in both 2D and 3D, with good integration between the optical and electrical in the numerical workflow.

To start the solar simulation, we can start with FTTD and calculate electrical and magnetic fields, absorption power, optical efficiency, generation rate, and ideal short circuit current density.

The generation rate calculated in FTTD goes to the charge, where we can calculate IV curves, short circuit current, open circuit voltage, recombination, and photovoltaic efficiency. For more information, you can look at our knowledge base article at the ANSYS website.

In the FTTD simulation, we calculate the electrical and magnetic fields, power, and absorption based on the electric and magnetic field. We can then calculate the transfer function of the system by the impulse response and generate photons in our structure.

In the charge simulation, we define a geometry material property and assign electrical, thermal, and optical properties. We can define a doping profile and simulate the temperature part.

The numerical charge simulation environment allows us to do steady state and dynamic simulations, see band structure, charge doping, mobility, and define different doping options. We can import doping from the outside and simulate for different voltage, with or without thermal effect.

We can then see the charge distribution and write a script to plot the IV curve and power efficiency. In the next step, we want to generate a temperature profile for the heat, for the charge. We need to do some thermal simulation to see the effect of thermal.

The blue one is the IV characteristic for the power with the effect of heat, and if we ignore the heat, the power is decreased. We can define a monitor and extract data for the numerical FDD. This is the heat distribution through the numerical heat.

Now we know how to define a material geometry, monitor solver, and generate a heat distribution. Let's look at some results. This is a silicon solar cell with MOS-I anti-reflection coating. The green one shows the transmission, and the red one shows the absorption.

The red one shows the transmission to the substrate. The absorption profile for the electric field in different wavelengths shows that the amount of absorbed power is much higher for 850 nanometers than for 350 nanometers. We can also use a plastic solar cell.

If we have a periodic structure and nanoparticles in our solar cell, we can see the effect of plasmonic enhancement. This is the field distribution for the nanoparticle in the photonic crystal in the periodical structure. The profile shows the field distribution without a nanoparticle.

This image shows the enhancement of solar cell efficiency due to the plasmonic effect. The solver and material geometry monitor solver allow us to define a material, geometry, and monitor solver. We can then look at some results. This is a silicon solar cell with MOS-I anti-reflection coating.

The green one shows the transmission, and the red one shows the absorption. The red one shows the transmission to the substrate. The absorption profile for the electric field in different wavelengths shows that the amount of absorbed power is much higher for 850 nanometers than for 350 nanometers.

We can also use a plastic solar cell. If we have a periodic structure and nanoparticles in our solar cell, we can see the effect of plasmonic enhancement. This is the field distribution for the nanoparticle in the photonic crystal in the periodical structure.

The profile shows the field distribution without a nanoparticle. This image shows the enhancement of solar cell efficiency due to the plasmonic effect. In conclusion, we are moving towards American crystal that has produced an innovative galvanic optic scattering effect.

We should focus on the convenient one and a photonic crystal. The band structure of a photonic crystal for t and tm mode shows a slow light region, which enhances conversion. We can plot the field distribution in different regions and change the parameter to see the effect of solar cell performance.

If we have a quantum well in our structure, we can define the quantum well structure and solve the schrodinger equation and drift diffusion equation in a dynamic workflow.

Ansys numerical is good for simulating structures in nano and micro scales, but sometimes we want to simulate in a bigger picture, like in a ray tracing regime. We have Zemax and can use the complete workflow in the Ansys website. If you have any questions, please send an email to info@ozonic.com.

If you need training material, you can contact training@ozonic.com. Thank you.