What is a Solar Cell and How Does It Work?

What is a Solar Cell and How Does It Work?

hat is a Solar Cell?

A solar cell, also known as a photovoltaic cell, is a device designed to convert sunlight directly into electrical energy. Made primarily of semiconducting materials, such as silicon, solar cells can absorb photons from sunlight and generate an electric current through a process called the photovoltaic effect.

Solar cell

( Source: Wikipedia )



How Do Solar Cells Work?

When sunlight strikes a solar cell, it excites the electrons in the semiconducting material, causing them to break free from their atoms and create a flow of charge. The structure of the semiconductor facilitates the movement of these electrons, guiding them through an electric circuit within the solar cell. This controlled flow of electrons produces direct current (DC) electricity.

Solar cell working principle

( Source: ACS )



A Short History of Solar Cell.

The history of solar cells dates back to the mid-19th century when the phenomenon of photovoltaic (PV) effect was first discovered by a French physicist named Alexandre-Edmond Becquerel in 1839. He found that certain materials produced electric current when exposed to light.


In the late 1800s, American inventor Charles Fritts created the first rudimentary solar cell using selenium coated with a thin layer of gold. Although it had low efficiency, it marked the beginning of harnessing sunlight for electricity generation.


Over the years, advancements were made in materials and technology. In the early 20th century, Albert Einstein published a paper explaining the theory behind the photoelectric effect, which further contributed to the development of solar cells.


In the 1950s, scientists at Bell Laboratories in the United States invented the first practical silicon solar cell, which achieved a conversion efficiency of around 6%. This breakthrough paved the way for further research and commercial applications.


In the following decades, solar cell technology continued to improve. More efficient and cost-effective solar cells were developed, leading to wider adoption of solar power in various applications such as space exploration, telecommunications, and remote power systems.


Today, solar cells are widely used in residential, commercial, and utility-scale solar power installations globally. They play a crucial role in the transition towards clean and renewable energy sources, contributing to a more sustainable future.



The Current Mainstream Solar Cell Technology Routes.

1, Crystalline silicon solar cell technology is divided into monocrystalline silicon and polycrystalline silicon. The advantage is that the photoelectric conversion rate is high, and the conversion rate can reach more than 21%. The disadvantage is that the price is relatively expensive. Crystalline silicon solar cell technology is the mainstream technology in the current market.


2, Thin-film solar cell technology has the advantage of less material usage and lower price. The major disadvantage is that the photoelectric conversion rate is only half that of crystalline silicon, and the conversion efficiency is only 6%-10%, so the market share has always been very low.


The difference of moncrystalline, polycrystalline and thin-film solar cell

( Source: Energy.gov )


3, New solar cell technology has the advantage of high conversion rate and low cost. Perovskite photovoltaic cells are expected to be the fastest new type of solar cell product to be mass-produced. The theoretical efficiency limit of single-junction perovskite cells can reach 33%, which is higher than crystalline silicon cells and thin film cells. However, the biggest disadvantage of perovskite photovoltaic cells is that the efficiency attenuation is relatively serious, and it will not be used on a large scale until the efficiency attenuation technology is solved.


Perovskite photovoltaic cells

( Source: Energy.gov )



Solar Cell Size Classification.

Solar cells are classified into different sizes based on their dimensions and surface area. The most common size classifications for solar cells are as follows:


Standard Solar Cell Sizes: These include the traditional or standard sizes that are widely used in the industry. The most common standard sizes are:
  • 156 mm x 156 mm (6 inches x 6 inches)
  • 156 mm x 156 mm (M2) - also known as Multi-crystalline
  • 156.75 mm x 156.75 mm (M2) - also known as Mono PERC (Passivated Emitter Rear Contact)


    Standard Module Sizes: Solar modules or panels are composed of multiple solar cells. The module size classification refers to the overall dimensions of the panel. Common standard module sizes include:

    • 60-cell module: Typically measures around 992 mm x 1650 mm or similar dimensions.
    • 72-cell module: Typically measures around 992 mm x 1956 mm or similar dimensions.
    • Other custom module sizes are also available depending on specific installation requirements.


    These size classifications are not exhaustive, and there may be variations or custom sizes available in the market. The size of solar cells and modules can impact the power output, efficiency, and overall system design in solar installations.

    Solar Cell Size Classification

    ( Source: https://www.dsneg.com )



    Solar Panels and Solar Cells: Energizing Together.

    Solar panels are composed of multiple solar cells interconnected to form a photovoltaic (PV) module. Each solar cell within the panel is responsible for converting sunlight into electricity through the photovoltaic effect.


    The relationship between solar cells and solar panels

    ( Source: FSEC )


    In other words, solar cells are the building blocks of solar panels. They are the small units that directly convert sunlight into electrical energy. Solar panels, on the other hand, consist of an array of these interconnected solar cells, which work together to generate usable electricity.


    So, the relationship between solar cells and solar panels is that solar cells are the essential components within a solar panel that directly convert sunlight into electricity, while solar panels are the complete modules that contain and connect multiple solar cells to generate usable electrical power.


    Solar cells are essential components of solar energy systems, converting sunlight into usable electrical energy through the photovoltaic effect. Their ability to harness the power of the sun offers numerous environmental, economic, and social benefits. As solar cell technology continues to advance, we move closer to a future powered by clean and sustainable energy sources. By embracing solar cells, we can pave the way towards a brighter, more sustainable world.



    Back to blog