Tailoring interfaces in Earth abundant thin film solar cells

Lead Research Organisation: Northumbria University
Department Name: Fac of Engineering and Environment

Abstract

Cu2ZnSn(S,Se)4 (CZTSSe) is a promising photovoltaic material with outstanding optoelectronic
properties and Earth abundant constituents. Among the variety of techniques employed for the
preparation of the absorber layer, solution-based deposition and processing has the potential to
provide low-cost scalable routes to produce photovoltaic devices with high efficiency. Such
results include the current record efficiency for CZTSSe solar cells at 12.6 % using hydrazinesolution
based method. On the other hand, nanoparticle inks offer an alternative to avoid using
the highly toxic and potentially explosive solvent, hydrazine. Deposited from the Cu2ZnSnS4
(CZTS) nanoparticle inks, the CZTS precursor thin films annealed in the presence of Se can
provide devices with efficiency up to 9.5%.
Northumbria has recently developed a route for fabricating and controlling the electronic and
structural properties of nanoparticle inks. Upon heat treatment a dense and compact film is
formed that can be used to fabricate solar cells with efficiencies approaching 7% on rigid
substrate or a bit less if we use flexible foils. Our attention now focuses on the interfaces within
the solar cell structure and particularly the pn junction.
The key aim of this project is to develop single/multilayer n-type buffer layers using
indium/cadmium/zinc sulphide and zinc/titanium oxide to increase device performance for both
rigid and flexible structures. During the study you will be in control of the complete fabrication
processes (nanoparticle inks, thin film and solar cells) and will have access to a wide range of
characterisation techniques and recently refurbished laboratories. You will also work closely with
one of our partners, TescanUK, to observe the layers nano/microstructure and chemical
composition while performing in-situ microscopy-stress tests (for example bending of flexible
films, heat treatment of the pn junction). This project is suitable for a candidate with strong
interest in semiconductor and device fabrication as well as spectroscopy and microscopy.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S023836/1 01/04/2019 30/09/2027
2283352 Studentship EP/S023836/1 01/10/2019 30/09/2023 Matthew Corlett Naylor