Abstract
Six different thin film solar cells consisting of either orthorhombic (α-SnS) or cubic (π-SnS) tin(ii) sulfide absorber layers have been fabricated, characterized and evaluated. Absorber layers of either π-SnS or α-SnS were selectively deposited by temperature controlled Aerosol Assisted Chemical Vapor Deposition (AA-CVD) from a single source precursor. α-SnS and π-SnS layers were grown on molybdenum (Mo), Fluorine-doped Tin Oxide (FTO), and FTO coated with a thin amorphous-TiO x layer (am-TiO x -FTO), which were shown to have significant impact on the growth rate and morphology of the as deposited thin films. Phase pure α-SnS and π-SnS thin films were characterized by X-ray diffraction analysis (XRD) and Raman spectroscopy (514.5 nm). Furthermore, a series of PV devices with an active area of 0.1 cm 2 were subsequently fabricated using a CdS buffer layer, intrinsic ZnO (i-ZnO) as an insulator and Indium Tin Oxide (ITO) as a top contact. The highest solar conversion efficiency for the devices consisting of the α-SnS polymorph was achieved with Mo (η = 0.82%) or FTO (η = 0.88%) as the back contacts, with respective open-circuit voltages (V oc ) of 0.135 and 0.144 V, and short-circuit current densities (J sc ) of 12.96 and 12.78 mA cm -2 . For the devices containing the π-SnS polymorph, the highest efficiencies were obtained with the am-TiO x -FTO (η = 0.41%) back contact, with a V oc of 0.135 V, and J sc of 5.40 mA cm -2 . We show that mild post-fabrication hot plate annealing can improve the J sc , but can in most cases compromise the V oc . The effect of sequential annealing was monitored by solar conversion efficiency and external quantum efficiency (EQE) measurements.
Original language | English |
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Pages (from-to) | 14899-14909 |
Number of pages | 21 |
Journal | RSC Advances |
Volume | 9 |
Issue number | 26 |
Early online date | 16 May 2019 |
DOIs | |
Publication status | Published - 16 May 2019 |
Funding
The authors thank the EPSRC and the University of Bath for funding (EP/G03768X/1 and EP/L017792/1), the EPSRC Centre for Doctoral Training in Sustainable Chemical Technologies for a PhD studentship and travel grant. Authors from IREC acknowledge the nancial support of Spanish Ministry of Science, Innovation and Universities by the WINCOST (ENE2016-80788-C5-1-R) project, and the European Regional Development Funds (ERDF, FEDER Programa Competitivitat de Catalunya 2007–2013). Authors from IREC belong to the SEMS (Solar Energy Materials and Systems) Consolidated Research Group of the “Generalitat de Catalunya” (Ref. 2017 SGR 862).
Keywords
- AACVD
- SnS
- Solar Cells
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering