Perovskite solar cells (PSC) are the fastest-growing solar cell technology in recent years. A remarkable power conversion efficiency (PCE) above 25% has been reached in a very short time, while at the same time perovskite are also compatible with silicon technology to form tandem solar cells. Despite their potential, due to stability concerns they mostly remain limited to laboratory use and within dimensions not exceeding a few square centimetres. As a solution to the above challenges, a niche application to use PSC to power indoor electronics, such as devices for Internet of things (IoT), has arisen. Besides the excellent PCE of these cells, also an efficient, low-power electronics is required.
In this paper, we present a commercially viable electronic circuit for harvesting energy from a single PSC and monitoring its parameters. Use of the latest Bluetooth standards and efficient integrated circuits can lower average consumption below 10 µA. This allows the use of supercapacitors for energy storage instead of the otherwise established Li-ion batteries, which simplifies the system. The feasibility of the concept was demonstrated by the development of a self-sufficient IoT device that is powered by a single laboratory PSC and stores energy in a supercapacitor. The device measures the intensity of light in the room and the parameters of the system, which are transmitted to the remote receiver and recorded there. Exploiting Bluetooth Low Energy (BLE) promotional channels enables efficient one-way wireless communication with a range of up to a few tens of meters and allows a few days of uninterrupted operation without solar energy when the supercapacitor is fully charged.
The prototype shows that today’s laboratory PSCs already allow the construction of autonomous sensor nodes with wireless communication. The good cell efficiency enables the generation of sufficient energy even indoors with quite small solar cells. By suitable design of electronics, long-term operation with very little energy can be achieved, enabling the practical application of perovskite solar cells to autonomously power IoT devices intended for indoor operation.
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