Used Tools:

Solar Cell

A solar cell (Figure 1), or photovoltaic cell (previously termed "solar battery"), is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.  It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as current, voltage, or resistance, vary when exposed to light. Solar cells are the building blocks of photovoltaic modules, otherwise known as solar panels.

Figure 1 -  Solar Cell

Application: As renewable energy safe and clean, solar cell is becoming used as an important source of energy. It is applied in many domains such home applications (Figure 2), industrial, public lighting, smart phone charge , aerospace (Figure 3).

Figure 2 - Solar Panels  used as source of energy in home


Figure 3 - International Space Station powered by solar panels

 

Why Simulate Solar Cells ?

• Improving PV efficiency
• Optimizing for design performance and target reliability
• Reducing the effects of variation on system performance
• Predicting manufacturing yields
• Lowering production costs 

Description of the problem

Continuous innovation makes cells more complex ( More process and geometrical variables – 3D effects, complex light path, etc …). This why it’s impractical to design new cells without simulation. EMS Electric Conduction Module offers the opportunity to simulate solar cell and avoid a lot of experiments which are needed to investigate design model. 

The model is a single cell from a solar panel (Figure 4). The cell consists of a pair of aluminum electrodes covering a silicon cell. The top electrode is a thin tapered body, and has an electric potential of 0.6V. The bottom electrode is a flat rectangle, acting as ground. The analysis focuses on determining the voltage drop across the silicon cell, and along the tapered end of the front electrode (figure 5). The electric field and the current density are the main analysis points.

Figure 4 - Solar Cell simulated model


Figure 5 - Solar Cell operations

Study

After creating an Electric Conduction in EMS, four important steps shall always be followed: 1 - apply the proper material for all solid bodies, 2- apply the necessary boundary conditions, or the so called Loads/Restraints in EMS, 3 - mesh the entire model and 4- run the solver. Note that for the Electric Conduction analysis no air shall be modeled.

Materials

In the Electric Conduction analysis of EMS,  only electric and thermal conductivity (in case of thermal coupling) are needed (Table 1).

Table1 - Table of materials

Load and Restraint

In this study, Only fixed voltages are applied

Table 2 - Applied Fixed Voltage

Meshing

Meshing is a very crucial step in the design analysis. EMS estimates a global element size for the model taking into consideration its volume, surface area, and other geometric details. The size of the generated mesh (number of nodes and elements) depends on the geometry and dimensions of the model, element size, mesh tolerance, and mesh control. In the early stages of design analysis where approximate results may suffice, you can specify a larger element size for a faster solution. For a more accurate solution, a smaller element size may be required.
Mesh quality can be adjusted using Mesh Control (Table 3), which can be applied on solid bodies and faces. Below (Figure 4) is the meshed model after using Mesh Controls.

Table 3 -  Mesh control

Figure 6 - meshed model

Results

After running the simulation of this example we can obtain many results. Electric Conduction of EMS is used to compute and Visualize  Electric Field(Figure 7,8), Current Density (Figure 9,10) and potential(Figure 11). A results table also generated contains the resistance and dissipated power.

EMS offer the possibility of many types of plot. Below we can observe fringe, line and vector plot.

Figure 7 - Electric Field, fringe plot


Figure 8 - Electric Field, line plot


Figure 9 - Current Density, fringe plot


Figure 10 - Current Density, vector plot


Figure 11 - Potential of solar cell

Conclusion

Simulation using EMS of multiple of studies with different parameters leads to more optimization of the solar cell.