1 research outputs found
Efficient Carrier Separation and Band Structure Tuning of Two-Dimensional C<sub>2</sub>N/GaTe van der Waals Heterostructure
Efficient
carrier separation and suitable band structure are critical
for developing better nanoscale optoelectronic devices. However, so
far, researchers have not developed a single material system that
can satisfy these requirements. Here we design a novel C<sub>2</sub>N/GaTe van der Waals heterostructure based on the density functional
theory. Our results suggest that this heterostructure is an indirect
band gap semiconductor (1.39 eV) with intrinsic type-II band alignment,
facilitating the separation of photogenerated carriers. Meanwhile,
this heterostructure exhibits improved visible optical absorption
compared with that of the isolate C<sub>2</sub>N and GaTe monolayers.
More fascinatingly, we find that an intriguing indirect-to-direct
band gap semiconductor transition can be induced at the compressive
strain of 3%. Simultaneously, the band gaps and carrier effective
masses can also be significantly reduced by the biaxial strain. Furthermore,
the band edge positions of C<sub>2</sub>N/GaTe heterostructure can
be effectively tuned to straddle the redox potentials of water splitting
by isoelectronic anion S and Se substitution at the Te site, and the
enhanced optical absorptions are also observed in the doped heterostructures,
indicating that S (Se)-doped C<sub>2</sub>N/GaTe heterostructures
are potential photocatalysts for water splitting. In addition, effective
spatial separation of photogenerated carriers is expected to occur
for all of the above cases. These findings suggest that the C<sub>2</sub>N/GaTe heterostructure is a promising candidate for application
in future nanoelectronics and optoelectronics devices and also provides
some valuable information for future experimental research