Conference paper
Semiconductor band alignment from first principles: a new nonequilibrium Green's function method applied to the CZTSe/CdS interface for photovoltaics
Department of Micro- and Nanotechnology, Technical University of Denmark1
Theoretical Nanoelectronics, Department of Micro- and Nanotechnology, Technical University of Denmark2
Center for Nanostructured Graphene, Centers, Technical University of Denmark3
Silicon Microtechnology, Department of Micro- and Nanotechnology, Technical University of Denmark4
QuantumWise A/S5
In this paper we present a method to obtain the band offset of semiconductor heterointerfaces from Density Functional Theory together with the nonequilibrium Green's function method. Band alignment and detailed properties of the interface between Cu2ZnSnSe4 and CdS are extracted directly from first principles simulations.
The interface is important for photovoltaics applications where in particular the band offsets are important for efficiency. The band bending pose a problem for accurate atomistic simulations of band offsets due to its long range. Here we investigate two different methods for dealing with band bending directly.
One involves doping the materials to induce a shorter screening length. The other method is to apply a voltage bias across the interface to correct for the band bending. The calculated band offsets agree well with previous experimental and theoretical studies and, interestingly, the offset is seen to depend on whether or not the interface is under flat-band conditions.
Language: | English |
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Publisher: | IEEE |
Year: | 2016 |
Pages: | 377-380 |
Proceedings: | International Conference on Simulation of Semiconductor Processes and Devices 2016 |
ISBN: | 1509008187 , 1509008195 , 9781509008186 and 9781509008193 |
Types: | Conference paper |
DOI: | 10.1109/SISPAD.2016.7605225 |
ORCIDs: | Crovetto, Andrea , Gunst, Tue , Hansen, Ole and Brandbyge, Mads |