What are photovoltaic cells made of?

Are you thinking of acquiring photovoltaic for your home? Wondering what are solar panels made of and how do they work? Find out more about the conversion of solar power to energy that can help you save on your energy bill every year! Here is everything you need to know before installing photovoltaics and before you start looking for a trustworthy PV provider and installer. 

Photovoltaics are skyrocketing in popularity everywhere in Europe, not just within companies and industry sites, but also in residential areas. With PV panels, families can save up to hundreds of euros a year on electricity, while simultaneously doing their part for the planet. The sun is an inexhaustible source of power, which makes it the most efficient renewable energy source for households and industries alike. And with the help of a spacious storage system, a solar battery, this energy can be stored during periods of heavy sunlight, and used on other days, such as during the winter or gloomy autumn. Many families have already installed their photovoltaic panels on the roofs of their homes, however, not many have had an interest in how such panels work and how they are structured. What is the magic that turns sun power into electricity? Find out in our article today. 

When sunlight hits a photovoltaic (PV) cell, also known as a solar cell, it can either reflect off, be absorbed, or pass through the cell. These cells are primarily made of semiconductor materials, meaning they can conduct electricity better than insulators but not as efficiently as metals. Various semiconductor materials are utilized in PV cells. 

Now, what is the photovoltaic cell working principle? When light interacts with the semiconductor material, it absorbs the energy and transfers it to negatively charged particles within the material, called electrons. This additional energy enables the electrons to move through the material, generating an electric current. Metal contacts on the PV cell, arranged in a grid-like pattern, extract this current, which can then be utilized to power homes and contribute to the electric grid. 

The efficiency of a PV cell is essentially the electrical power produced by the cell compared to the energy from the incident light. This metric indicates the cell's effectiveness in converting energy from one form to another. The electricity output from PV cells is influenced by factors such as the intensity and wavelengths of available light, as well as various performance attributes of the cell. 

A crucial characteristic of PV semiconductors is the bandgap, which determines the wavelengths of light the material can absorb and convert into electrical energy. The bandgap is the distance between the valence band of electrons and the conduction band. It represents the minimum energy required to excite an electron up to a state in the conduction band where it can participate in conduction. When the bandgap of the semiconductor matches the wavelengths of the incident light, the solar cell can efficiently utilize all available energy. 

As of now you know how solar cells work, it is time to investigate the material that makes solar power into solar energy. Several types of solar cell need a different type of solar cell material. Now, let us delve into the most used photovoltaic materials list for PV cells: 

Thin-film solar cells are crafted by depositing one or more thin layers of PV material onto a supporting substrate such as glass, plastic, or metal. Two main types of thin-film PV semiconductors dominate the market: cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS). While CdTe cells offer cost-effective manufacturing processes, their efficiencies still lag behind silicon. CIGS cells boast promising properties for PV applications but face manufacturing complexities. Both materials require enhanced protection compared to silicon for prolonged outdoor operation. 

Silicon stands as the most prevalent semiconductor material used in solar cells, accounting for approximately 95% of the modules sold today. It is also the second most abundant material on Earth, following oxygen, and widely utilized in computer chips. Crystalline silicon cells consist of silicon atoms interconnected to form a crystal lattice, providing an organized structure that enhances the conversion of light into electricity. These silicon-based solar cells offer a blend of high efficiency, low cost, and long lifespan, often lasting for 25 years or more while retaining over 80% of their original power output. 

Perovskite solar cells, a subtype of thin-film cells, derive their name from their distinctive crystal structure. These cells incorporate layers of materials deposited onto a substrate. Perovskite cells are relatively easy to assemble and exhibit efficiencies comparable to crystalline silicon. Efficiencies have rapidly improved in the lab, but commercial viability hinges on enhancing durability for extended outdoor use and developing cost-effective manufacturing techniques. 

Quantum dot solar cells leverage tiny semiconductor particles, mere nanometers in size, to conduct electricity. While they offer novel semiconductor processing methods, challenges remain in establishing efficient electrical connections. Quantum dots come in varying sizes with customizable bandgaps, enabling light collection optimization and integration with other semiconductors for enhanced performance, such as perovskites. 

Organic PV (OPV) cells comprise carbon-rich compounds and offer customization potential for specific PV cell functions. Despite being about half as efficient as crystalline silicon cells with shorter lifespans, OPV cells present opportunities for cost-effective mass production. Their adaptability to various supporting materials, including flexible plastics, widens their potential applications. 

Concentration PV (CPV) concentrates sunlight onto a solar cell using mirrors or lenses, requiring less PV material. This concentration enhances PV material efficiency, but it demands more expensive materials and precise sun tracking, posing challenges in achieving cost advantages over traditional silicon modules. 

Multijunction solar cells employ multiple semiconductor layers with different bandgaps to capture a broader solar spectrum, achieving higher efficiencies compared to single-junction cells. While multijunction cells have demonstrated efficiencies exceeding 45%, their production remains expensive and complex, primarily reserved for specialized applications like space exploration and military drones. 

In this article you were introduced to all diverse types of solar cell material. Although the information might seem more technical and difficult to process, there is no need to feel overwhelmed. Your chosen installer has all the information you need for you to start effectively using your photovoltaic panels and start saving energy and the planet. If you need any extra information about photovoltaics, do not hesitate to have a look at our other articles, or contact your trusted installer.