A highly-sensitive and highly-integrated flexible broadband imager with 3D printed $\pi$-shaped photo-thermoelectric pixel structures

To push forward existing multi-functional terahertz (THz) imaging applications, such as flexible and broadband operation with carbon nanotube (CNT) film-based photo-thermoelectric (PTE) imagers, the high-density pixel integration is essential. This paper proposes a fusion between CNT film absorbers and easily printable flexible thermoelectric modules (TEGs) to design a highly-sensitive, highly-integratable, three-dimensional $\pi$-shaped PTE pixel structure. A simple transfer printing enables vertical alignment of Bi2Te3-based PN TEG pairs on a flexible substrate. The CNT film surface channel functions as the efficient heat transfer induced by the external THz irradiation to the vertical TEG structure.