Nonlinear resonances of plasma waves in field-effect transitors enable a well-known photodetection mechanism, first introduced by Dyakonov and Shur in the 1990s, especially suited to the Terahertz (THz) frequency range. Theoretical analyses of the mechanism always assume that the gate of the transistor, which is coupled to the antenna receiving the THz signal, is as long as the channel itself, at odds with typical experimental devices based on III-V compounds or graphene, where short gates are usually employed, e.g., due to fabrication constraints. In this work we overcome this limitation and provide a complete theory of Dyakonov-Shur photodetection in the presence of short gates. We develop our theory in such a general fashion that allows us to also treat the case in which multiple gates are present. We find that a suboptimal positioning of the gates can substantially decrease the detection efficiency of the device and provide a compact analytical formula to quickly estimate the optimal gate position.

Close

PrevNext

View figure in article

• Hydrodynamic waves
• Photoconductivity
• Photocurrent
• Plasma oscillations
• 2-dimensional systems
• Field-effect transistors
• Graphene
• Two-dimensional electron gas