Azure Photon develops perovskite solar cells to replace disposable batteries

The world appears to be becoming ever more reliant on disposable batteries. “In 2025 alone, 78 million batteries will have been discarded every day, with a significant economic and environmental impact,” says Azure Photon, a new spin-off from the Faculty of Engineering at the University of Porto. The company is proposing a clean, “long-life” alternative designed to last for more than a decade.

Official estimates suggest that, by 2030, more than 40 billion IoT (Internet of Things) devices will be operating. Although many of these products have a working life close to 10 years, their batteries need replacing every two years on average, creating “a growing mountain of electronic waste”. These include small devices such as temperature, humidity, motion and air-quality sensors, smart labels, meters, monitoring systems and countless items that collect and transmit data continuously, as well as wireless keyboards.

Azure Photon was created with this challenge in mind, aiming to replace conventional batteries with perovskite solar cells that can harvest energy from indoor lighting and power smart devices throughout their entire lifespan.

A crystal developed in the laboratory

The technology created by Seyedali Emami and Jorge Martins, researchers at LEPABE – the Laboratory for Process Engineering, Environment, Biotechnology and Energy – alongside Adélio Mendes, a full professor in FEUP’s Department of Chemical and Biological Engineering, uses perovskite solar cells. Perovskite is a crystal found in nature, but it can also be manufactured in the laboratory with light-absorbing properties.

“It is an emerging photovoltaic technology made from abundant, low-cost materials, distinguished by its exceptional ability to generate electricity even in low-light conditions. In indoor environments, these cells have already achieved a record energy-conversion efficiency of 44.7%, substantially outperforming traditional silicon and thin-film solar technologies,” the researchers explain.

In practical terms, they say, the technology “makes it possible to turn the artificial lighting in offices, warehouses, shops or smart homes into a clean, continuous and sufficient energy source for powering sensors and IoT devices without the need for ongoing maintenance”. This is achieved using a laser hermetic-sealing process that shields the photovoltaic cells from moisture and oxygen, two of the leading causes of deterioration. It also relies on a process developed at FEUP that operates at temperatures below 100 degrees, whereas conventional methods require more than 400 degrees Celsius, making them unsuitable for the sensitive materials used in perovskites.

2,500 hours of stability for Azure Photon solar cells

According to the company, cells encapsulated in this way have already shown more than 2,500 hours of stability in accelerated tests under solar illumination, a result regarded as “essential to the project’s commercial viability”.

The next phase is to launch the first device, providing an energy alternative capable of cutting electronic waste, lowering operating costs and increasing the autonomy of the smart devices underpinning the digitalisation of buildings, industries and infrastructure, “in line with European carbon-neutrality targets and the United Nations Sustainable Development Goals”, they say.

Azure Photon says its batteries are far more sustainable than current alternatives and “are easily adaptable to existing sensors”, Jorge Martins notes. He adds that potential customers span several sectors, including industry, construction, supermarkets and freight transport logistics. However, he acknowledges that “it is still very difficult to compete with traditional batteries in terms of cost. We are talking about a very early-stage technology compared with the mass production of disposable batteries”.

Two projects under way

“At present, we are talking about prices of 50 cents to €1 for disposable batteries and €3 for our solution, already at production scale, with one million batteries as a minimum,” the researcher says. He is confident that the company’s production can become competitive within five years, “depending on funding and the market”.

For now, Azure has two projects under way. One, under StartUP Voucher Innovate 2025–2026, is worth €30,000 and was used to create three prototypes of electronic devices powered by solar cells, as well as market studies. The other, funded through Norte 2030, has an allocation of €900,000 for manufacturing solar cells, developing prototypes and carrying out field validation in real buildings.

“What we need to do now is move from the laboratory to commercialisation,” the researcher says of this project, which began with a doctoral thesis and is starting to draw the attention of potential international clients. Interest is especially strong in the construction and retail sectors, where a single supermarket may have more than 7 million electronic labels, all powered by batteries.