Integrated TRNG and PUF Based on Room-Temperature Phosphorescent Polymer Dielectric Gated Phototransistors

Harnessing the entropy of multiple transitions between different electronic states in room-temperature phosphorescence (RTP) not only overcomes the drawbacks of authentication via afterglow but also holds significant potential for cryptographic protocols that are immune to attacks from future quantum computers. However, such an objective has yet to be realized. Here, RTP films are incorporated as a dielectric layer in phototransistors, which give two distinct outputs, i.e., phosphorescence (I_p) from the dielectric layer and photocurrent (I_d) across the source-drain electrode. The susceptible thermodynamics of electron transitions and the triplet-to-singlet energy transfer at the dielectric-semiconductor interface causing I_p to vary with each readout, thereby enabling true random number generator (TRNG) functionality. Whereas I_d is mainly governed by film quality and interfacial defects, which vary among different batches due to inherent randomness introduced during fabrication, making it suitable as a physical unclonable function (PUF). Detailed studies reveal that the two outputs demonstrate excellent uniqueness and independence, with a Hamming weight of 0.50, an inter-Hamming distance of 50.27%, a Pearson correlation coefficient of -0.0054, and an encoding capacity of 2²⁵ within a 5 × 5 transistor array. This work represents a breakthrough of integrated optoelectronic devices for highly secure authentication while also inspiring new applications for RTP materials.