Organic solar cells (OSCs) present an eco-friendly and sustainable alternative to traditional solar cells, offering greater design flexibility and lower production costs.

While the adoption of silicon-based solar panels continues to grow—over 1.6 million installations were recorded in the UK by the end of July 2024—there are increasing concerns about the environmental impact of these panels.

The manufacturing and disposal processes for silicon solar cells can involve potentially hazardous materials, raising questions about their long-term sustainability.

In contrast, organic solar cells provide a more environmentally conscious and recyclable solution, making them an appealing option for those seeking greener solar energy technologies.

In this article, we’ll explore the benefits and challenges of OSCs, and their potential to shape the future of solar energy.

What Are Organic Solar Cells?

OSCs, also known as organic photovoltaic (OPV) cells, convert sunlight into electricity using carbon-based organic materials like small molecules and polymers.

These materials can be synthesized in the laboratory using low-cost printing methods.

Traditional solar cells use inorganic materials like silicon or cadmium telluride, which require extensive mining and processing.

Organic solar cells leverage the properties of organic compounds and can be processed into thin, flexible layers.

How Do Organic Solar Cells Work?

OPV cells absorb photons of light and generate an electrical current through the flow of electrons in the organic material.

The basic structure of an organic solar cell consists of a photoactive layer sandwiched between two electrodes.

The photoactive layer comprises donor and acceptor materials. The donor material absorbs sunlight and generates excitons (electron-hole pairs).

These excitons are then split at the donor-acceptor interface, allowing electrons and holes to travel to opposite electrodes, generating an electric current.

What Are the Benefits of Organic Solar Cells?

Flexible and Lightweight

Unlike rigid silicon panels, OSCs can be made thin and flexible, allowing integration into various surfaces, including building facades, windows, and even wearable electronics.

Such adaptability opens up new possibilities for incorporating solar power into everyday life, from solar-powered fabrics and backpacks to building-integrated photovoltaics like transparent windows that generate electricity.

Low-Cost Manufacturing

Organic solar cells can be produced using low-cost materials like metal foils or plastic and simple manufacturing techniques like roll-to-roll printing, inkjet printing, or spray coating.

Such methods resemble newspaper printing, making it possible to produce large-area solar cells quickly and at a lower cost compared to conventional silicon panels.

The printing technique also enables customization and the creation of unique designs and shapes.

Environmentally Friendly

Organic solar cells are made from non-toxic materials like carbon-based polymers and are free of expensive and rare materials like metals and silicon.

As a result, they’re more eco-friendly and present fewer disposal challenges compared to their inorganic counterparts. OSCs are also recyclable into new cells or other products.

Transparency and Tunability

Organic solar cells’ transparent characteristics give them a natural advantage over other types of PV cells.

They’re ideal for applications like solar windows or skylights that combine energy generation with natural light transmission, allowing easy incorporation into buildings without compromising aesthetics.

OSCs also feature high tunability, allowing easy modification to meet specific application requirements.

The organic materials used in PV cells allow for a high degree of control over the cell’s electrical and optical properties.

What Are the Challenges Facing Organic Solar Cells?

Limited Efficiency Compared to Silicon Solar Cells

One of the main drawbacks of organic solar cells is their lower conversion efficiency. OSCs usually have an efficiency of 10-20%, while traditional silicon solar cells routinely achieve efficiencies above 20%.

The lower efficiency is due to the inherent properties of organic materials, including lower charge mobility and higher recombination rates of excitons. It limits the power output of OSCs, which may not be enough for certain applications.  

Stability and Durability Issues

Organic solar cells face significant challenges in terms of stability and durability.

Organic materials are prone to degradation when exposed to oxygen, moisture, and ultraviolet light, which can reduce the lifespan of OSCs to just a few years.

This is a major hurdle when compared to silicon panels, which can last 25 years or more.

Efforts to improve stability through encapsulation and material engineering are underway, but achieving the long-term reliability of traditional solar technologies remains a critical challenge.

Scalability and Manufacturing Consistency

While OSCs offer the potential for low-cost, large-scale production, scaling up the technology from lab settings to commercial-scale manufacturing has proven difficult.

Issues such as maintaining consistent film thickness, uniformity, and defect-free production at scale can affect the performance and yield of OSCs.

Additionally, developing compatible and scalable materials for electrodes, substrates, and encapsulation adds complexity to the commercialization process.

Check out our video review of the best solar panels in the UK:

What is the Potential Impact of Organic Solar Cells on the Future of Solar Energy?

Integration into Urban Environments

Organic solar cells’ flexibility, lightweight nature, and semi-transparency make them ideal for urban environments with limited space for traditional solar panels.

They can easily blend into building materials such as windows, facades, and roofs, turning urban spaces into power-generating surfaces.

The potential to blend with existing infrastructure could revolutionize how cities approach renewable energy, making solar power more accessible and widespread.

Enhancing Off-Grid Applications

Organic solar cells can enhance off-grid and portable applications, such as powering remote sensors, wearable devices, or temporary installations.

Their ease of installation and lightweight design make them a practical choice for situations where conventional solar panels would be too cumbersome or costly.

Complementing Existing Solar Technologies

Rather than competing directly with silicon-based solar cells, organic solar cells are likely to complement existing technologies by filling niches where traditional panels are less effective.

For example, OSCs are suitable for applications that require lightweight, flexible, or semi-transparent solutions, creating opportunities for hybrid systems that combine the strengths of multiple photovoltaic technologies.

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Final Thoughts

Organic solar cells’ reduced environmental impact in terms of material use, manufacturing energy, and disposal makes them an attractive option for the future of green energy.

However, they still face challenges like lower efficiency, stability, and durability.

Sources and References

• https://www.gov.uk/government/statistics/solar-photovoltaics-deployment