When French technology company Dracula Technologies showcased its new generation of indoor photovoltaic cells at CES earlier this month, it signalled a potential step forward in powering battery-free connected devices.
The company has made a name for itself generating electricity from ambient indoor light, including low-intensity LED sources.
Its new system, LAYER V2.0, now claims a 30% improvement in performance under real-world indoor lighting conditions.
IoT Insider spoke with Jérôme Vernet, VP Strategy and co-founder of Dracula Technologies, to learn more about the technology and its potential applications.
IoT: What is LAYER V2.0 and why is it 30% better than the previous generation?
JV: We developed a unique way to manufacture organic photovoltaic (OPV) modules using inkjet printing, called LAYER. Building on the first successful and promising generation, we enhanced the performance by 30%. This improvement is the result of a combined optimization of chemistry, physics, and manufacturing processes.
IoT: How has LAYER V2.0 achieved that?
JV: Building on the foundations established with LAYER, this new generation benefits from new raw ink materials. The most significant advancement with this new generation is the development of a new active material ink that substantially improves the energy generation capabilities of OPV modules. This next-generation ink introduces two key innovations that enhance overall performance: Better light absorption: With new blue active materials, the active area absorbs more light in the visible spectrum. This increases overall energy capture, particularly under limited indoor lighting conditions where ambient sources such as LEDs provide reduced light intensity. Higher conversion efficiency: The next-generation ink delivers improved electrical performance compared to the previous ink generation. This results in a higher open-circuit voltage, typically between 0.7 and 0.8 volts per cell.
IoT: What is it actually made of?
JV: In an OPV module, the active layer is an organic hydrocarbon layer composed primarily of carbon (C) and hydrogen (H). When this active layer absorbs light photons, it generates electron-hole pairs. These pairs are separated by an internal electric field, producing an electric current that can be extracted outside the module via conductors known as bus bars. A conductive layer collects the current generated by the active layer. In OPV modules, this function is performed by two electrodes: the bottom electrode, typically made of indium tin oxide (ITO), and the top electrode. ITO is both electrically conductive and transparent, allowing light to reach the active layer. The top electrode completes the circuit while ensuring efficient current collection with minimal impact on light absorption.
IoT: Why is this important?
JV: Beyond the chemistry and physics involved, LAYER enables new applications that cannot be addressed by traditional batteries or grid-connected solutions.
Wherever there are people, there is light, natural or artificial, direct or indirect, even at low levels. This is precisely where LAYER is most relevant. Low-light environments are where LAYER becomes a game changer compared to other energy-harvesting technologies. Our energy-harvesting solutions can replace batteries entirely, extend battery lifetime, or recharge certain battery types, significantly reducing maintenance and waste in IoT deployments.
IoT: How does energy harvesting from ambient indoor light help reduce reliance on disposable batteries in IoT applications?
JV: LAYER V2.0 enables applications that cannot be realistically supported by batteries or wired power. When deploying hundreds of thousands or even millions of devices, relying on batteries that must be replaced and recycled is neither scalable nor sustainable. This is the right moment for new IoT applications that require small, compact, sustainable, and affordable energy solutions for data collection. At the same time, we see strong optimization of sensor and electronics power consumption, combined with rapidly increasing demand for high-volume deployment.
IoT: How does inkjet printing contribute to both performance and customization of LAYER V2.0 modules?
JV: Inkjet printing allows us to deposit only the necessary amount of raw material, avoiding over-consumption. Material is placed precisely where needed, following a digital design approach similar to a standard graphic printer. This provides great design flexibility with virtually no limitations. There is no need for masks or patterns, and we can optimize the active area while minimizing dead zones, directly improving module efficiency.
IoT: What tangible benefits does the improved performance of LAYER V2.0 offer to OEMs and system designers?
JV: The key ones are: higher power – for a module using the same OPV cell surface area, OEMs can achieve up to 30% higher power output without increasing the module footprint.
Also the smaller footprint and lower cost means that for applications requiring the same energy generation, OEMs can reduce the active surface area by approximately 30%. This leads to a smaller module footprint and a corresponding reduction in module cost.
IoT: How do changes to bus bars and the introduction of a decorative top coating improve aesthetics and integration?
JV: Previous-generation OPV modules used copper bus bars to collect charge from the active layer. Copper requires a minimum line width of around 3 mm to ensure reliable attachment to the substrate, which limits design flexibility and increases dead zones, reducing the effective active area. In LAYER V2.0, copper bus bars have been replaced with silver bus bars. Silver offers excellent conductivity while allowing much finer line widths. As the bus bar width decreases, dead zones shrink and overall power capacity increases, depending on module layout.
Copper deposition has been replaced with screen printing using a silver paste. This technique enables precise control of line width, with resolutions as fine as 0.5 mm. Silver also provides a more uniform visual appearance than copper.
Additionally, copper bus bars typically have a thickness of around 60 µm (micrometres) while OPV layers are approximately 1 µm thick. This mismatch can lead to visual defects such as trapped air bubbles. Screen-printed silver reduces bus bar thickness to 10–15 µm, better bridging the gap and reducing defect risk. Finally, a new decorative top coating has been introduced to enhance both robustness and appearance. This coating improves scratch resistance and mechanical durability while enabling more discreet and aesthetically refined OPV designs. OEMs can choose from different finishes depending on their application needs.
IoT: Why is LAYER V2.0 particularly well suited to low-light or intermittent light environments such as warehouses?
JV: Compared to other existing technologies, LAYER already provides one of the best solutions for low-light environments. With enhanced performance, LAYER V2.0 further strengthens this advantage, making it especially well-suited for indoor and intermittently lit environments such as warehouses.
IoT: What future innovations and applications is Dracula Technologies targeting as it continues to develop its OPV technology?
JV: Future developments include new raw materials, further simplification of the production process, and the reuse of parts of Dracula Technologies’ intellectual property for other markets, such as indium tin oxide (ITO) replacement, particularly for flexible and sustainable electronic applications.
