Abstract-Negative photoconductivity and hot-carrier bolometric detection of terahertz radiation in graphene-phosphorene hybrid structures

Journal of Applied Physics

V. Ryzhii, M. Ryzhii, D. S. Ponomarev, V. G. Leiman,  V. Mitin,  M. S. Shur,  T. Otsuji,

The structures of (a) the GP-LD and (b) the GP-FET (b), their asymmetric with respect to the Dirac point (Δe>Δh${\mathrm{\Delta }}^e>{\mathrm{\Delta }}^h$) energy band diagrams with the G-Dirac cones and the parabolic extrema corresponding to the P-layer at (c) T=T0$T=T_0$ and (d) T>T0$T>T_0$ (T$T$ and T0$T_0$ are the carrier effective temperature and the lattice temperature, respectively), and (e) the energy dependence of the density of state (DoS). Open circles correspond to the holes in the valence bands of G- and P-layers.

https://aip.scitation.org/doi/abs/10.1063/1.5054142

We consider the effect of terahertz (THz) radiation on the conductivity of the ungated and gated graphene (G)-phosphorene (P) hybrid structures and propose and evaluate the hot-carrier uncooled bolometric photodetectors based on the GP-lateral diodes (GP-LDs) and GP-field-effect transistors (GP-FETs) with the GP-channel. The operation of the GP-LDs and GP-FET photodetectors is associated with the carrier heating by the incident radiation absorbed in the G-layer due to the intraband transitions. The carrier heating leads to the relocation of a significant fraction of the carriers into the P-layer. Due to a relatively low mobility of the carriers in the P-layer, their main role is associated with a substantial reinforcement of the scattering of the carriers. The GP-FET bolometric photodetector characteristics are effectively controlled by the gate voltage. A strong negative conductivity of the GP-channel can provide much higher responsivity of the THz hot-carriers GP-LD and GP-FET bolometric photodetectors in comparison with the bolometers with solely the G-channels.