We study the electronic properties of two-dimensional (2D) group-III nitrides BN, AlN, GaN, InN, and TlN by first-principles approaches. With increasing group-III atomic number, a decrease of the electronic gap from 6.7 eV to 0 eV takes place. 2D GaN and 2D InN in honeycomb geometry present a direct gap at Γ, while the honeycomb structures of BN and AlN tend to be indirect semiconductors with the valence band maximum at K. Alloying of the nitrides allows tuning the gap with cation composition. Interestingly, Inx Ga1-xN and Inx Tl1-xN alloys enable, with varying x, to construct type I or type II heterostructures. We demonstrate that it is possible to tailor the electronic and optical response from UV to IR. We suggest that 2D InGaN and InTlN heterostructures may efficiently harvest light and serve as building blocks for a future generation of III-V solar cells. Finally, 2D InTlN with a low In content is eligible as the emitter and detector for THz applications.
Prete, M.S., Mosca Conte, A., Gori, P., Bechstedt, F., Pulci, O. (2017). Tunable electronic properties of two-dimensional nitrides for light harvesting heterostructures. APPLIED PHYSICS LETTERS, 110(1), 012103 [10.1063/1.4973753].
Tunable electronic properties of two-dimensional nitrides for light harvesting heterostructures
GORI, Paola;
2017-01-01
Abstract
We study the electronic properties of two-dimensional (2D) group-III nitrides BN, AlN, GaN, InN, and TlN by first-principles approaches. With increasing group-III atomic number, a decrease of the electronic gap from 6.7 eV to 0 eV takes place. 2D GaN and 2D InN in honeycomb geometry present a direct gap at Γ, while the honeycomb structures of BN and AlN tend to be indirect semiconductors with the valence band maximum at K. Alloying of the nitrides allows tuning the gap with cation composition. Interestingly, Inx Ga1-xN and Inx Tl1-xN alloys enable, with varying x, to construct type I or type II heterostructures. We demonstrate that it is possible to tailor the electronic and optical response from UV to IR. We suggest that 2D InGaN and InTlN heterostructures may efficiently harvest light and serve as building blocks for a future generation of III-V solar cells. Finally, 2D InTlN with a low In content is eligible as the emitter and detector for THz applications.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.