Abstract-InP double heterojunction bipolar transistors for terahertz computed tomography

AIP Advances

Dominique Coquillat, Alexandre Duhant, Meriam Triki, Virginie Nodjiadjim, Agnieszka Konczykowska, Muriel Riet, Nina Dyakonova, Olivier Strauss, Wojciech Knap

(a) Schematic of the InP DHBT THz detector and read-out circuit connections. (b) Input characteristics IBE − VBE of the 3-finger device. Inset: SEM photograph of a 3-finger DHBT with 3 × 10 μm × 0.7 μm emitter area. (c) Photo-voltage ΔU (left hand scale) and area normalized voltage responsivity RmeasV$R_V^{meas}$ (right hand scale) as a function of frequency for VBE = 0.43 V.

https://aip.scitation.org/doi/abs/10.1063/1.5039331

We present experimental studies of terahertz radiation detection by InP double heterojunction based transistors. We analyze the relation between their static characteristics and the experimentally determined voltage and current responsivities, showing importance of internal device parasitic capacitances and the external circuit loading effects. Finally, we demonstrate the use of these transistors for terahertz radiation computed tomography leading to 3D visualization of concealed objects. Our results pave the way towards wide use of heterojunction based transistors for terahertz imaging.