Gate tunable WSe2/SnSe2 backward diode with ultrahigh reverse rectification ratio

TL;DR

This paper demonstrates a gate-tunable WSe2/SnSe2 backward diode with an ultrahigh reverse rectification ratio of about 2.1x10^4, showing potential for advanced electronic applications due to its high performance and tunability.

Contribution

It introduces a van der Waals heterojunction backward diode with record-high reverse rectification ratio and tunable transport properties, outperforming existing diode technologies.

Findings

Achieved an ultra-high reverse rectification ratio (~2.1x10^4).

Maintained high rectification ratio up to 1.5 V bias.

Demonstrated tunability via gate voltage, bias, and layer thickness.

Abstract

Backward diodes conduct more efficiently in the reverse bias than in the forward bias, providing superior high frequency response, temperature stability, radiation hardness, and 1/f noise performance than a conventional diode conducting in the forward direction. Here we demonstrate a van der Waals material based backward diode by exploiting the giant staggered band offsets of WSe2/SnSe2 vertical heterojunction. The diode exhibits an ultra-high reverse rectification ratio (R) of ~2.1x10^4 and the same is maintained up to an unusually large bias of 1.5 V - outperforming existing backward diode reports using conventional bulk semiconductors as well as one- and two-dimensional materials by more than an order of magnitude, while maintaining an impressive curvature coefficient ({\gamma}) of ~37 per V. The transport mechanism in the diode is shown to be efficiently tunable by external gate and drain bias, as well as by the thickness of the WSe2 layer and the type of metal contacts used. These results pave the way for practical electronic circuit applications using two-dimensional materials and their heterojunctions.