Study of ZnSnN2 (ZTN) thin-film deposition by High-Power Impulse Magnetron Sputtering (HiPIMS) and analysis of material properties to assess its application as a top absorber layer in tandem solar cells on Si. The characterisation includes morphological, structural, compositional, optical and electrical analyses. Optimisation of ZTN by substrate polarisation led to a reduction in intrinsic doping. Band gap was estimated in approx. 1.55 eV.<\/p>\n","protected":false},"author":93,"featured_media":0,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"tags":[1300,1328],"targets":[1304,1317],"rapporti_tipologie":[762],"class_list":["post-209579","rapporti","type-rapporti","status-publish","hentry","tag-industrial-sector","tag-photovoltaics","targets-industrial-world","targets-research","rapporti_tipologie-report-en"],"acf":{"dont_show_hompage":true,"projects":{"ID":188400,"post_author":"464","post_date":"2024-06-13 15:10:01","post_date_gmt":"2024-06-13 13:10:01","post_content":"","post_title":"Integrated High Efficiency Photovoltaic Project","post_excerpt":"The goal of this project is to facilitate the development of high-efficiency, low-cost photovoltaic (PV) generation systems, while helping to maximize the energy production of the plants in Italy.","post_status":"publish","comment_status":"open","ping_status":"closed","post_password":"","post_name":"integrated-high-efficiency-photovoltaic-project","to_ping":"","pinged":"","post_modified":"2024-07-03 11:13:04","post_modified_gmt":"2024-07-03 09:13:04","post_content_filtered":"","post_parent":0,"guid":"https:\/\/www.rse-web.it\/progetti\/integrated-high-efficiency-photovoltaic-project\/","menu_order":0,"post_type":"progetti","post_mime_type":"","comment_count":"0","filter":"raw"},"order_posts":"","dont_show_search":false,"related_posts":false,"show_on_slider":false,"single_post_data":{"titolo_spot":"","post_content":"
The project investigated the deposition of ZnSnN2 nitride (ZTN) thin films by reactive sputtering in the DC (Direct Current) and HiPIMS (High-Power Impulse Magnetron Sputtering) regimes, to investigate the feasibility of the process and to study ZTN for photovoltaic applications in tandem solar cells with Si. Deposition parameters were investigated to optimise ZTN films, and several characterisation techniques were applied, such as SEM, EDX, XRD, Raman, ellipsometry and electrical analysis.<\/p>\n
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The importance of the Zn\/Zn+Sn ratio in the films was highlighted, with 0.67 as a critical threshold to avoid uncontrolled oxidation. With DC sputtering, increasing the substrate temperature improved crystallinity and reduced oxygen content. Compositional control of the material was achieved for both regimes. With HiPIMS, at room temperature, it was shown to be possible to synthesise ZTN films with morphology and crystallinity comparable to those obtained in DC with substrate heating (> 200 \u00b0C), and the application of polarisation enabled ZTN to be optimised by reducing the free carrier concentration down to 2.5×1018<\/sup> cm-3<\/sup>. By means of ellipsometry, a band value of approximately 1.55 eV was estimated, consistent with the literature, and refractive index and extinction coefficient were determined.<\/p>\n <\/p>\n In addition, ohmic (Au and Au\/Ni) and rectifying (Ag) contacts on ZTN were identified, crucial for electrical measurements. The ohmic nature of the contact between ZTN and various substrates (FTO, ITO and Mo) was also determined, although some instability of the film on them was detected. Also, degradation over time, observed mainly on ZTN deposited via HiPIMS and attributed to oxidation of the film, needs further investigation.<\/p>\n <\/p>\n In conclusion, HiPIMS sputtering made it possible to deposit ZTN of excellent quality even at room temperature, with superior characteristics to those obtained with the DC process. In the future, it will be necessary to research doping and band gap control to realise ZTN as a top absorber in tandem cells on Si. The literature suggests that ZnSnN2<\/sub> can become p-type by doping with Li, which acts as a shallow acceptor replacing Zn. However, limiting unintentional n-type doping is challenging and interstitial Li can generate donor sites, making the dopant ineffective. Instead, band gap engineering, to obtain values approaching 2 eV, requires the introduction of additional elements (e.g. Ge, Ti) to form quaternary alloys.<\/p>\n <\/p>\n The Report is available on the Italian site<\/strong><\/p>\n","link_estreno":false,"scarica_file":false,"button":{"text":"","link":""},"referente_group":false,"data_emissione":"2024-12-31","autori":"F. Annoni, .E Achilli, N. Armani, M. Cornelli (RSE S.p.A.), D. Dellasega, C. Mancarella, D. Vavassori (Politecnico di Milano), M. Patrini (Universit\u00e0 di Pavia)","rapporto":"","rif_rse":"24013439"},"satellite_post_url":""},"yoast_head":"\n