Open AccessNumerical analysis of electronic state of CNT/BNNT heterojunction
Author(s) -
Mitsuyoshi Tomiya,
Shoichi Sakamoto,
Toshihiro Sagara,
Masaki Yamamoto,
Masahiro Ito
Publication year - 2022
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2207/1/012038
Subject(s) - heterojunction , materials science , density functional theory , fermi level , siesta (computer program) , condensed matter physics , band gap , rectangular potential barrier , density of states , diode , semiconductor , electronic band structure , electron , optoelectronics , ab initio quantum chemistry methods , chemistry , computational chemistry , physics , quantum mechanics , organic chemistry , molecule
The I-V characteristics of CNT/BNNT heterojunctions, which comprise quantum double barrier systems (DBS), were numerically investigated using density functional theory (DFT) calculations and the non-equilibrium Green’s function (NEGF) method. First, we performed a structural optimisation of the DBS of CNT/BNNT. Next, the I-V characteristics of the heterojunctions were calculated using the SIESTA package. The I-V characteristics remain flat up to a certain bias voltage, and then the current increases with increasing voltage. Our CNT/BNNT double-barrier heterojunctions have resonant states inside the barriers as semiconductor-based double-barrier diodes; these states determine the transmission function. An energy gap was centred at the Fermi energy and sharp peaks in the gap were observed. It was also found that the energy interval of the peaks near the Fermi energy was dependent on the separation length of the two BNNT barriers. Using projected density of states (PDOS) analysis, we also investigated the local behaviour of electrons in the devices.