Semiconductor band alignment from first principles: a new nonequilibrium Green's function method applied to the CZTSe/CdS interface for photovoltaics

Mattias Lau Nøhr Palsgaard, Andrea Crovetto, Tue Gunst, Troels Markussen, Ole Hansen, Kurt Stokbro, Mads Brandbyge

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

Abstract

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.
Original languageEnglish
Title of host publication2016 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD)
Number of pages4
PublisherIEEE
Publication date2016
Pages377-380
ISBN (Print)978-1-5090-0819-3
ISBN (Electronic)978-1-5090-0818-6
DOIs
Publication statusPublished - 2016
EventInternational Conference on Simulation of Semiconductor Processes and Devices 2016 - Le Meridien Grand Hotel, Nuremberg, Germany
Duration: 6 Sep 20168 Sep 2016
http://www.sispad2016.org/

Conference

ConferenceInternational Conference on Simulation of Semiconductor Processes and Devices 2016
LocationLe Meridien Grand Hotel
Country/TerritoryGermany
CityNuremberg
Period06/09/201608/09/2016
Internet address

Keywords

  • Semiconductor process modeling
  • Photonic band gap
  • Doping
  • Photovoltaic cells
  • Performance evaluation
  • Electric potential
  • Discrete Fourier transforms

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