Theoretical Understanding of Perovskite Solar Cell Materials with use of Density Functional Theory

Lead Research Organisation: University of Surrey
Department Name: ATI Electronics

Abstract

This project involves the use of Density Functional Theory and surrounding techniques to describe the structural and electronic properties of various Perovskite solar absorber materials. These materials are well understood experimentally but there are still gaps in the theoretical understanding of the more complicated triple cation systems. These systems are necessary to improve stability while maintaining excellent power conversion efficiencies as well as the removal of the prescence of toxic lead from these systems. This study begins with the categorisation of the widespread benchmark material MAPbI3. It then moves onto the modelling of lead free inorganic and inorganic-organic hybrid Perovskite material systems. This process begins with structural characterisation and moves onto bandstructure based electronic structure calculations to reveal the absorber properties of these materials to aid with experimental fabrication of cheap and high stability high efficiency solar cells. This project will inform a large group of experimentalists in the optimum design considerations of future Perovskite solar cells.

Publications

10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509772/1 01/10/2016 30/09/2021
1922310 Studentship EP/N509772/1 03/07/2017 31/01/2021 Cameron Underwood
 
Description Perovskite solar cells have rapidly reached high efficiencies at low costs, but suffer due to a lack of device stability. One major issue of stability is due to oxidation, especially in lead-free Sn based perovskites. An analysis of the ASnI3 system where A = CH3NH3, CH3N2H2 or Cs is undertaken where the system is neutrally charged or 2+ charged, this provides a model to infer information about the oxidised perovskite system.

Ruddlesden-Popper perovskites of the form An+1BnX3n+1 where n = the number of layers are a single/multi layer perovskite system that have increasing stability with decreasing layers n. A study for n=1 Ruddlesden-Popper perovskites has been undertaken for a mixed alloy B site of Pb-Sn, the different permutations have been studied and the resulting non-linear bandgap characteristics as a function of composition have been calculated and compared to 3D bulk perovskite materials.
Exploitation Route The charged cell model can be used to study the oxidation of other perovskite combinations, as well as set an example of a study for oxidation of a single atom, not just the entire cell.

The Ruddlesden-Popper perovskite research has made a foundation for studying mixed alloy 2D perovskites. An even larger plethora of material types are left to study for this, as well as varying the value of layers n. The permutations used in this study can be used as a template for others, even with varying A or X sites, as well as layers n.
Sectors Energy,Environment

 
Description Collaboration with Zhengzhou 
Organisation Zhengzhou University
Country China 
Sector Academic/University 
PI Contribution Primary research on 3D Sn based perovskites undertaken at University of Surrey.
Collaborator Contribution Research collaboration on computational techniques and research, primarily for 3D Sn based perovskite research. Contributions include method of atomic relaxation, and plan to implement charged cell method as well as supervision and advice throughout.
Impact Outcomes relevant to 3D Sn perovskite charged cell study. Paper being written up currently.
Start Year 2018
 
Description Poster Presentations 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Poster presentation at University of Surrey Doctoral College 2018 and Next generation materials for solar photovoltaics 2020. Poster taken to International Conference on Advanced Materials Modelling 2019 but unfortunately had to leave before presenting.
Year(s) Of Engagement Activity 2018,2019,2020