Scalable Room-Temperature Terahertz Graphene Cameras

Terahertz (THz) imaging has emerged as a powerful tool for non-destructive, label-free analysis across several scientific disciplines, ranging from materials science to biomedical research. By capturing the spatial-dependent information in a broad range of frequencies, this technique enables the identification of chemical composition, structural heterogeneity, and dynamic processes in complex samples. However, the practical deployment of hyperspectral or broadband THz imaging has been limited by the performance, cost, and scalability of conventional detector technologies. In this work, we present two architectures of cameras based on large-area arrays of graphene field-effect transistors (GFETs), operating at room temperature, in a broadband configuration, and at terahertz frequencies. The devised GFET-based detectors exploit the photo-thermoelectric effect and are optimized for wideband sensitivity through on-chip broadband antenna design and gate-tunable responsivity. We thoroughly characterize the performance of individual pixel elements and introduce optimized multiplexed readout circuitry tailored for each configuration. Our GFET-based THz cameras exhibit exceptional performance metrics, including a noise equivalent power (NEP) on the order of nanowatts per square root hertz (nW/Hz^1/2) and maximum responsivities reaching 36 V/W. Additionally, the pixel-to-pixel uniformity in sensitivity and electrical characteristics significantly reduces the complexity of calibration and control, enabling scalable implementations for large-format arrays.