Electrodes as the protagonists in composite barrier Ferroelectric Tunnel Junctions

The role of electrodes in composite barrier Ferroelectric Tunnel Junctions (FTJs) is investigated for the systems (//Pt/STO/BTO/SRO, //Pt/STO/BTO/Pt, //SRO/STO/BTO/SRO and // SRO/STO/ BTO/Pt). The tunneling current is controlled by the potential drop in the accumulation and depletion region in the electrodes which depends on the ratio of their screening length to permittivity (delta/epsilon). The Tunneling electro resistance ratio (TER) becomes significant for bias potential V > |P| (delta(1)/ epsilon(1) +t(d)/ epsilon(d) + delta(2) /epsilon(2))wherein the screening charge density sigma(s) remains negative causing the pull-down of the barrier towards the Fermi level and an increase in the tunneling current. Among the studied systems //Pt/20 angstrom STO/24 angstrom BTO/SRO system with an active device length of 7.6 nmis found to have a current density of 3.38x10(4) A cm(-2) and 0.22 A cm(-2) in the ON and OFF state and an absolute TER of around 1.52x10(5)% at the bias of 0.77 Vconform to the necessary conditions of efficient application in memory devices.

Automated summary

The role of electrodes in composite barrier Ferroelectric Tunnel Junctions (FTJs) has been investigated, and it has been found that the tunneling current is controlled by the potential drop in the electrodes, which depends on the ratio of their screening length to permittivity. Under certain conditions, the Tunneling electro resistance ratio (TER) becomes significant, leading to an increase in the tunneling current. Among the studied systems, the //Pt/20 angstrom STO/24 angstrom BTO/SRO system shows promising current density and TER, making it a potential candidate for efficient application in memory devices.