Photovoltaic Cell: An Informative Overview

A photovoltaic cell or a solar PV cell constitutes a solar panel. Solely responsible for capturing solar energy and generating DC power, they are combined for maximum power generation. A single silicon solar cell holds the potential to produce around 0.5 to 0.6 volts of electricity. 

Capturing energy through the photovoltaic effect, solar photovoltaic cells are types of metals like silicon, cadmium, gallium arsenide, and other varieties. However, a silicon solar PV cell is widely preferred. 

The eco-friendly approach of utilising solar energy over non-renewable energy resources reduces carbon footprint and is cost-effective. 

Apart from domestic use, PV solar cells are commercially utilised in factories, toys, calculators, radios, chargers, and even vehicles.

Does a photovoltaic cell seem interesting to you? If so, let’s help you discover what they are in great detail. 

What is a Photovoltaic Cell?

A solar photovoltaic cell has non-mechanical semiconductor diodes that use physical and chemical properties to transform photons from the sun into electrical energy. These semiconductors absorb sunlight through the optical coating, which is anti-reflective to minimise wastage. 

The PV solar cells vary between 0.5 to 4 inches in size and join together to form solar panels. They are further combined through multiple ways to form an array responsible for bulk electricity generation. 

The photovoltaic cell efficiency is determined as the ratio between electric power generated to the received amount of sunlight. Theoretically, the maximum efficiency is around 33%, termed the Shockley-Queisser limit, which eventually modulates electric power output. 

Now that you have understood PV cells, let’s talk about how they are made.

Manufacturing of PV cells

The production method of solar cells involves the purification of silicon, followed by making single-crystal silicon, which is eventually converted into silicon wafers. The doping process adds impurities to the silicon wafers, which assists in creating the electron disbalance required for the conduction of electric current. 

• Fine electrodes are placed at the top and bottom layers. 
• Anti-reflective coating is another important component, as pure silicon reflects around 35% of the sunlight. 
• For maximum utilisation of the renewable energy source, titanium dioxide and silicon oxide coatings are used. 
• The next step is encapsulating the formed solar photovoltaic cell into ethylene vinyl acetate or silicon rubber. 
• These are further placed into aluminium frames with glass or plastic overs on top. 

Now let’s look into multiple and best types of solar cells.

Types of solar cells

Based on the material, a solar PV cell is of multiple types. 

• Amorphous silicon solar cells
• Biohybrid or hybrid solar cells
• Quantum dot solar cells
• Organic solar cells
• Monocrystalline and polycrystalline solar cells
• Perovskite solar cells
• Gallium arsenide germanium
• Dye-sensitised solar cell

Out of numerous options, silicon solar cells find applications in a wide range. Silicon solar cells are of further three types – monocrystalline, polycrystalline, and amorphous silicon solar cells. 

Further narrowing down based on use, monocrystalline and polycrystalline are widely employed. Monocrystalline silicon solar cells are more efficient due to their structure of pure silicon. Consuming less space, these are expensive and operate for a longer duration. 

Polycrystalline silicon solar cells constitute multiple silicon crystalline cells that decrease efficiency and decrease prices; thus, increasing affordability. However, they require more space. 

How does a photovoltaic cell perform its function?

Containing p-type and n-type silicon, the former layer contains one excess electron compared to the latter. The silicon has the normal number of electrons. The absorbed sunlight or photons hit the top layer of p-type silicon, releasing electrons. 

The ‘free’ electrons roam around to fill the ‘holes.’ in n-type silicon (created by released electrons). Now the p-n junction contributes to the electric current through the translocation of holes and electrons. 

Power generation depends on the location based on the:

• Amount of daylight
• Weather conditions
• System design and capacity
• Shading and roof orientation
• Air pollution
• Efficiency of panels
• Temperature 

Curious about the price range? The next section will enlighten you.

What is the price range of solar cells?

The price of solar cells depends on factors like silicon content and capacity of the solar system, determined by the number of solar cells and mode of array connection. 

• Polycrystalline silicon solar cells are cheaper. They’re priced at about ₹25.5 per watt.
• Monocrystalline silicon solar cells, being more efficient, are expensive. They’re priced at about ₹31 per watt. 

Based on the capacity of the system, the price range is tabulated below. 

Pros and limitations of solar photovoltaic cell

Pros:

• Applicable for commercial as well as domestic solar installations 
• Provides a renewable and clean source of energy
• Reduces electricity consumption from the grid; thus, reducing the utility bill
• It is sustainable 

Limitations:

• High installation charges that vary according to the size
• Requires energy storage in case of an off-grid system and hybrid system

Conclusion 

Solar cells are the building blocks of solar panels. Silicon monocrystalline and polycrystalline photovoltaic cells are the most popular. 

The power generation mechanism is simple to understand, and the price range varies depending upon multiple factors. With numerous benefits over limitations, the latest technical approach is a great gift to the world. 

FAQs

1. What are multiple silicon solar cell types?

Monocrystalline, polycrystalline, and amorphous silicon solar photovoltaic cells are type of silicon-based solar cells.

2. What does a photovoltaic cell connect with for current transmission?

The photovoltaic cells are connected with electrodes on the top and bottom layer to transfer the electric current.

3. Are solar cells used only for domestic purposes?

Solar cells find wide applications in industries and commercial space alongside their domestic application.