By Prof. Ahmed Ennaoui,
President of the Scientific Council of IRESEN – Institut de Recherche en Energie Solaire et Energies Nouvelles
member of International Solar Energy Society (ISES)
member, of Institute of Electrical and Electronics Engineers (IEEE).
In order to reduce the cost and improve manufacturing efficiencies, a number of products will be based on the introduction of Internet technologies, better defined as Industry 4.0. This will change the way companies and consumers communicate worldwide. In this talk we will introduce digital manufacturing (e.g. additive manufacturing (AM) and inkjet printing) of thin film and related devices as a case to fit with Industry 4.0. We will highlight how digital inkjet printing can be used “On demand” for devices manufacturing such as: (1) ink formulation of raw materials; (2) inkjet printing deposition; (3) patterning; (4) encapsulation which can be scaled up in a roll-to-roll (R2R) process. Inkjet printing can be seen as an additive process for PV industry sector and allowed to create thin film materials, fine and small feature size with high precision by non-contact drop on Demand (D-O-D) inkjet printed ink with reduced material waste. Inkjet printing holds promise and potential for cost reductions, in the solar PV Industry as compared to traditional lithographic techniques. The proof of concept concerns the transfer of the spin coating for the fabrication of chalcopyrite Cu(In,Ga)(SxSe1-x)2 (CIGSSe) and kesterite Cu2ZnSn(SxSe1-x)4 (CZTSSe) to a printing process. This holds several challenges and requires new approaches and skill sets compared to the vacuum processing, (e.g. the annealing step is a must). We will present our proof of concept for efficient CIGS and CZTS solar cells [1‐4]. Finally we will discuss the Oxford-‐PV printing technology for processing perovskite and Cu(In,Ga)(S,Se)2 (CIGS) as top and bottom cells, respectively. This project is very promising since a proof of concept for perovskite/CIGS tandem thin-film solar module with 17.8 percent was achieved by KIT, ZSW, and imec, and this can be implemented by inkjet printing [5,6]. Regarding Silicon manufacturing, digital inkjet printing is already implemented throughout certain steps of manufacturing, e.g. to replace photolithography in rear-‐side patterning for passivated-emitter-rear contact (PERC) and for front-‐grid metallization as alternative to replace screen-‐printed especially for thinner wafers. The talk could open the discussion regarding the technological aspect to use digital inkjet printing for full solar cell manufacturing.
 X. Lin , J. Kavalakkatt, M. Lux-Steiner, and A. Ennaoui.
Inkjet-Printed Cu2ZnSn(S,Se)4 Solar Cells, Advanced Sciences (2015), Vol. 2, Issue 6, DOI: 10.1002/advs.201500028
 X. Lin, A. Ennaoui, R. Klenk, S. Fiechter, A. Ennaoui, M. Lux-Steiner.
11.3% efficiency Cu (In, Ga)(S,Se)2 thin film solar cells via drop-on-demand inkjet printing, Energy & Environmental Science (2016) 9 (6), 2037-‐2043. DOI: 10.1039/C6EE00587J 2016
 Ahmed Ennaoui et al. Challenges for the development of inkjet printed Cu25Zn,Sn)5S,Se)4 Thin Film Solar Cell. Proceeding of ISES Solar World Congress, November 8-‐12, 2015, Daegu/Korea
Ahmed Ennaoui is Physician and material scientist, President of the Scientific Council of IRESEN – Institut de Recherche en Energie Solaire et Energies Nouvelles. He was Professor at Hamad Bin Khalifa University (HBKU) and Research Director of Solar Energy group at Qatar Environmental and Energy Research Institute (QEERI). Prior to joining QEERI, he was working at the Hahn-Meitner Institute-Berlin (HMI) conducting research for his Habilitation with professor Helmut Tributsch, in the “Abteilung Solare Energetik” working on new earth abundant materials for solar energy conversion. He then promoted senior scientist and project leader at Hahn-Meitner Institute-Berlin and Helmholtz Zentrum Berlin für Materialien und Energie (HZB). During this time at HMI and HZB he developed state-of-the-art capabilities for processing thin films and related solar cells. He was promoted in 2000, to head research group and project leader pursuing research on several EU’s Framework programs and funding projects financed by the German Federal Ministry of Education. Meanwhile, he conducted successful feasibility studies financed by the industry (Siemens/Shell-Solar/Avancis, Solibro, Bosch, Atotech). Dr. Ahmed research interests are primarily focused on emerging thin film PV technology, from planar films to nanostructures including 2D Van der Waals (VdW) layered materials (WS2, MoS2, …), including the conversion of light into chemical and electrical energy, and photocatalysis of water splitting and reduction of surface state through of hydrogen terminated silicon for solar energy conversion.
At QEERI, he was managing research team, recruiting top scientists and developing novel methods allowing Drop on-Demand (D-O-D) patterning of materials with negligible materials waste and small environmental footprint such as inkjet printing technology. His published work on thin film solar cells with earth abundant materials for thin- film solar cells such as Kesterite Cu2ZnSn(SxSe1-x)4 (CZTSSe) and Cadmium free chalcopyrite Cu(In,Ga)(SxSe1-x)2 (CIGSSe) solar cells has been recognized with h-index 39. He granted several patents, he is author and co-author for more than 200 peer-reviewed journal articles including numerous conference contributions, and 4 special issues.
Dr. Ahmed is very active in academic teaching and tutorial work of advanced PV materials and innovative new solar cell concepts. He was involved in the evaluation of renewable energy seminar program for graduate students at Free University Berlin, Germany.
He was visiting professor at Osaka University/Japan. He taught several graduate courses and seminars on Advanced Thin Film materials for PV application at the Research Center for Solar Energy Chemistry, Graduate School of Engineering Sciences of Osaka University. He serves as full professor of physics at University Mohamed V (Morocco) for almost 25 years.
Dr. Ahmed is permanently member of the editorial Board of Solar Energy Materials and Solar Cells, President of the Scientific Council of the Moroccan Solar Energy Institute “IRESEN”, member of International Solar Energy Society (ISES), member of IEEE and chair of the scientific technical committee for the International Renewable and Sustainable Energy Conference (IRSEC)