Pt/PbSe optoelectronic receivers designed for 6G and terahertz communication technologies

Abstract

Herein PbSe thin films are coated onto glass and semitransparent platinum substrates. The films which are treated as optoelectronic signal receivers are deposited by the thermal evaporation technique under a vacuum pressure of 10− 5 mbar. The structural investigations have shown that (glass, Pt)/PbSe films are of polycrystalline nature. Optically, Pt substrates increased the transparency and reflectivity of PbSe films. The energy band gap of PbSe is also increased by 0.12 eV when films are coated onto Pt substrates. In addition the dielectric constant also increased as a result of strong interaction between Pt plasmonic particles and lead selenide. On the other hand, fitting of the imaginary part of the dielectric constant using Drude–Lorentz model has shown that coating of PbSe onto semitransparent Pt substrates increased the drift mobility of lead selenide by four times. Pt substrates resulted in a decrease in the density of free charge carriers and increases the scattering time constant at femtosecond levels. (Glass, Pt)/PbSe optoelectronic receivers displayed plasmon frequencies up to ~ 13 GHz and showed terahertz cutoff frequency of ~ 1.0 THz. In addition, allowing the propagation of an ac signal of low amplitude in the Pt/PbSe/Pt receivers has shown that the devices exhibit wide range of resistance tunability. The microwave cutoff frequency also reached 14 GHz. Both of the optical and electrical measurements proved the suitability of the Pt/PbSe devices for 6G and terahertz communication technologies.