Quantum confinement and band offsets in amorphous silicon quantum wells

Quantum confinement and band offsets in amorphous silicon quantum wells

Jarolimek, K.
De Groot, R.A.
De Wijs, G.A.
Zeman, M.

Electrical Engineering, Mathematics and Computer Science

Electrical Sustainable Energy

2014-09-18

Quantum wells (QWs) are nanostructures consisting of alternating layers of a low and high band-gap semiconductor. The band gap of QWs can be tuned by changing the thickness of the low band-gap layer, due to quantum confinement effects. Although this principle is well established for crystalline materials, there is still controversy for QWs fabricated from amorphous materials: How strong are the confinement effects in amorphous QWs, where, because of the disorder, the carriers are localized to start with? We prepare an atomistic model of QWs based on a-Si:H to gain insight into this problem. The electronic structure of our atomistic QWs model is described with first-principles density functional theory, allowing us to study the confinement effects directly. We find that the quantum confinement effect is rather weak, compared to experimental results on a similar system.

http://resolver.tudelft.nl/uuid:aaa42ebd-13d5-4e91-b9fc-299c88629314

https://doi.org/10.1103/PhysRevB.90.125430

American Physical Society

1098-0121

http://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.125430

Physical Review B, 90 (12), 2014

Institutional Repository

journal article

© 2014 American Physical Society