TY  - JOUR
AU  - Sasioglu, Ersoy
AU  - Aull, Thorsten
AU  - Kutschabsky, Dorothea
AU  - Blügel, Stefan
AU  - Mertig, Ingrid
TI  - Half-Metal–Spin-Gapless-Semiconductor Junctions as a Route to the Ideal Diode
JO  - Physical review applied
VL  - 14
IS  - 1
SN  - 2331-7019
CY  - College Park, Md. [u.a.]
PB  - American Physical Society
M1  - FZJ-2020-02649
SP  - 014082
PY  - 2020
AB  - The ideal diode is a theoretical concept that completely conducts the electric current under forward bias without any loss and that behaves like a perfect insulator under reverse bias. However, real diodes have a junction barrier that electrons have to overcome and thus they have a threshold voltage VT, which must be supplied to the diode to turn it on. This threshold voltage gives rise to power dissipation in the form of heat and hence is an undesirable feature. In this work, based on half-metallic magnets (HMMs) and spin-gapless semiconductors (SGSs) we propose a diode concept that does not have a junction barrier and the operation principle of which relies on the spin-dependent transport properties of the HMM and SGS materials. We show that the HMM and SGS materials form an Ohmic contact under any finite forward bias, while for a reverse bias the current is blocked due to spin-dependent filtering of the electrons. Thus, the HMM-SGS junctions act as a diode with zero threshold voltage VT and linear current-voltage (I-V) characteristics as well as an infinite on:off ratio at zero temperature. However, at finite temperatures, non-spin-flip thermally excited high-energy electrons as well as low-energy spin-flip excitations can give rise to a leakage current and thus reduce the on:off ratio under a reverse bias. Furthermore, a zero threshold voltage allows one to detect extremely weak signals and due to the Ohmic HMM-SGS contact, the proposed diode has a much higher current drive capability and low resistance, which is advantageous compared to conventional semiconductor diodes. We employ the nonequilibrium Green’s function method combined with density-functional theory to demonstrate the linear I-V characteristics of the proposed diode based on two-dimensional half-metallic Fe/MoS2 and spin-gapless semiconducting VS2 planar heterojunctions.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000553429500001
DO  - DOI:10.1103/PhysRevApplied.14.014082
UR  - https://juser.fz-juelich.de/record/878131
ER  -