A Self-Powered Optoelectronic In-Sensor PUF Based on Halide Perovskites

Ubiquitous sensing devices across multiple application domains continuously gather, consume, accumulate and transfer a massive volume of information, which needs to be safeguarded against malicious attackers. To this end, security measures need to be integrated into sensing devices. One of the ways to achieve this is to leverage the inherent variability between sensors induced during the manufacturing process which can be used to generate unique and unpredictable input and output combinations. Based on this premise, a single-device optical physically unclonable function (PUF) built from halide perovskite photovoltaics based on methylammonium bromide has been introduced. The photovoltaic architecture and superior light sensitivity offer a unique approach for a self-powered in-sensor PUF. Owing to the complex interplay of ionic and electronic processes in halide perovskites and manufacturing variations, each device responds uniquely, but reproducibly, to varying optical inputs. As a result, each device provides multiple untraceable encryption keys to implement a single device multibit PUF. The PUF shows a good uniformity of 46.52% and a notable peak around 50% for bit-aliasing frequency. It also shows remarkable reliability, as indicated by a minimal coefficient of variance of 1–2% in open-circuit voltage across 105 cycles. We also propose a strong PUF construction by integrating four independent weak PUFs, which exponentially increases the challenge-response pair space to 216. This research lays the groundwork for the development of highly reliable multibit optical PUFs, which can be useful for advanced product verification and antitheft purposes.