Performance-Improved Vertical Zr/Diamond Schottky Barrier Diode With Lanthanum Hexaboride Interfacial Layer

We have demonstrated performance-improved vertical diamond Schottky barrier diode (SBD) by introducing a lanthanum hexaboride (LaB
₆
) interfacial layer between Zr and diamond. The composition of LaB
₆
was characterized using X-ray photoelectron spectroscopy. The fabricated diamond SBD with LaB
₆
delivers a rectification ratio of 10
¹⁰
, a Schottky barrier height (SBH) of 1.53 eV, a saturation current density of 1.82×10
^-19
A/cm
²
, and a shunt resistance of 2.67×10
¹²
Ω. These results indicate that with the inclusion of LaB
₆
, diamond SBD exhibits improved SBH and reverse breakdown capability. Additionally, the trap-limited space-charge-limited current (SCLC) remains the determinant transport mechanism for diamond SBD with LaB
₆
. Meanwhile, the interface states density is significantly reduced due to the effect of LaB
₆
. These results suggest the great potential of vertical Zr/LaB
₆
/p-diamond SBD as future high-performance power rectifiers.