Ricerca su celle fotovoltaiche innovative

Accordo di Programma MSE-ENEA RICERCA DI SISTEMA ELETTRICO Ricerca su celle fotovoltaiche innovative Paola Delli Veneri ENEA Una o più immagini specifiche per il progetto Energia elettrica da Fonte solare - Roma, 27 maggio 2015

Company Technologies Modules delivered in 2014 (in MWp) Trina Solar (China) Wafers, crystalline (mono) cells, modules 3660 Yingliu Green Energy (China) Wafer, mono and multi crystalline cells, modules 3361 Canadian Solar (Canada, China) Ingots, wafer, cells, modules, PV systems 3105 Jinko Solar (China) Ingots, wafer, mono and multi cells, modules, 2944 JA Solar (China) Mono/poly crystalline, modules 2407 Renesola (China) Poly silicon wafer and modules, micro inverters 1970 Sharp Corporation (Japan) Crystalline (mono, multi) and thin film Si modules 1900 Motech (Taiwan) Crystl. cells (mono, multi) and modules, inverters 1632 First Solar (USA) Thin film modules (CdTe) 1500 Sun Power (USA) crystalline (mono, multi) cells, modules 1254 Top 10 PV modules producers in 2014 Source: EurObserver 2015 PV cell/module production Source: PV Status Report 2014, Arnulf Jager- Waldau European Commission, DG Joint Research Centre

Price-experience curve for solar modules PV system average price without financing and VAT: Eur 1400/kWp Cumulative PV Installation from 2005 to 2014 Source: PV Status Report 2014, A. Jager- Waldau European Commission, DG Joint Research Centre

PV State of Art Tecnology Efficiency (%) Area (cm 2 ) Institution 4 HIT (a-si/c-si), n-type c-si 25,6 144 Panasonic Si (multicrystalline) 20,8 244 Trina Solar Thin film Si (tripla giunzione) 13,4 1 LG electronic Thin film CIGS 21,7 0,5 ZSW CZTSS (thin film) 12,6 0,4 IBM solution grown Thin film CdTe 21,0 1 First Solar Perovskite thin film 20,1 0,1 KRICT- Korea Organic (thin film) 11,1 0,16 Mitsubishi Chemical Martin A. Green et al., Solar cell efficiency tables (version 45),Prog. Photovolt: Res. Appl. 2015; vol 23 (1),p:1 9.

Two possible approaches to the PV Research Development of extremely low cost PV technologies using available and not hazardous materials: Thin film silicon solar cells Thin film Cu 2 ZnSnS 4 (CZTS) solar cells Thin film organic solar cells Multijunction solar cells for highly efficient devices with silicon bottom cell

Silicon wafer-based tandem Cells: The ultimate PV solution for high effciency? Martin A. Green, Proceedings of 28th EUPVSEC, (2013), p.7. Bottom cell: Silicon Top cell:???? Present PV activities funded by MSE Heterojunction a-si/c-si solar cells Cu 2 ZnSnS 4 (CZTS) based solar cells Perovskite based solr cells

Recent past and next future in ENEA in the Research on the Electric System Thin film silicon solar cells Organic solar cells Perovskite based solar cell Next talks. Heterojunction a-si/c-si CZTS solar cells Light management strategies in solar cells

Advanced thin film silicon PV Micromorph andem solar cells blue Sun light glass a-si:h 1.75eV c-si:h 1.1eV ZnO/Ag red TCO p i n p i n Optimization of micromorph tandem cells by means of silicon oxide based doped materials; Development of innovative absorber layers for utilization in tandem cells; Evaluation of new architectures for an optical improvement of the thin film Si device performance J SC (ma/cm 2 ) 14 12 10 8 6 4 2 V OC = 1.3 V J SC = 12.1 ma/cm 2 FF = 71.9% = 11.3% 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Voltage (V)

Advanced thin film silicon PV: Development of mixed-phase n-sio x Dark Field TEM / Ag EFTEM Si-ncs sizes ~ 2.5 3 nm no ZnO Tunable n, k, μc-si ZnO Ag n-sio x : n ~ 2.5 P Delli Veneri et al., Appl. Phys. Lett. 97, 023512 (2010) P Delli Veneri et al., Progress in Photovoltaics 21, 148 (2013) LV Mercaldo et al., SOLMAT 119, 67 (2013) LV Mercaldo et al., SOLMAT 136, 32 (2015)

Advanced thin film silicon PV: Development of mixed-phase p-sio x :H Optical properties The novel p-layer allows: Lower absorption losses; better refractive index matching at the TCO/Si interface. EQE of solar cells with different p-layers Electrical properties LV Mercaldo et al, Proc of 28th EUPVSEC (2013) p. 2588.

Advanced thin film silicon PV: a-sio x :H top absorber Optical characterization of a-sio x :H layers VHF-PECVD @ 40 MHz Gas mixture: SiH 4, CO 2, H 2 J-V characteristic of a cell grown on flat substrate (glass/zno) p-i-n solar cells on Asahi substrates V OC = 1.01 V P. Delli Veneri et al, Proc of 29th EUPVSEC (2014) p. 1634.

Polymer solar cells Donors P. Morvillo et al, Solar Energy Materials and Solar Cells, 104, 45-52, 2012 P. Morvillo et al, Polymer Chemistry, 5, 2391-2400, 2014 A. Bruno et al, Thin Solid Films, 560, 14-19, 2014. C. Diletto et al, Journal of Sol-Gel Science and Technology, 73, 634-640, 2015. C. De Rosa et al, Physical Chemistry Chemical Physics, 17, 8061-8069, 2015. Acceptors

Externa Quantum Efficiency (%) Polymer solar cells Synthesis of new copolymers to be used as donor materials in devices PolyS PolyA 60 50 PolyA:[70]PCBM PolyS:[70]PCBM 40 Blend (1:1 wt) PCE (%) FF (%) J sc (ma/cm 2 ) V oc (mv) PolyS :[70]PCBM 2.30 48 7.0 672 PolyA :[70]PCBM 0.56 28 3.1 664 30 20 10 0 400 500 600 700 Wavelength (nm)

Current Density (A/cm 2 ) Nanostructured block copolymer to improve electrical transport PS-b-PMMA Al PMMA PS ITO Glass The electric field allows to align the nanostructures 0.02 0.01 0wt% PCBM 5wt% PCBM 10wt% PCBM 0.00-0.01 Films PS-b-PMMA with PCBM (5wt%) -0.02-4 -2 0 2 4 Voltage (V)

Polymer solar cells Eff= 10.1 % FF= 69.3 % Jsc= 18.0 ma/cm 2 Voc= 792 mv Device structure: GLASS ITO/ZnO PTB7-Th:PCBM MoO3 Ag

Perovskite based solar cells Crystal structure of cubic metal halide perovskite CH 3 NH 3 Pb Halogen ion (I, Cl, Br)

Perovskite solar cells CH 3 NH 3 PbI 3 deposition Film di perovskite depositati su diversi substrati

Current density (ma/cm 2 ) Current density (A/cm 2 ) Perovskite solar cells Mesoporous TiO 2 0.010 0.005 0.000-0.005 V OC = 715 mv J SC = 10.4 ma/cm 2 FF=44.9% = 3.3% Schematic structure of the solar cell without a hole transporter material -0.010-0.015-0.2 0.0 0.2 0.4 0.6 0.8 Voltage (V) Layers under investigation: Perovskite: CH 3 NH 3 PbI 3, CH 3 NH 3 PbI 3-x Cl x 5 0-5 -10 IV-light (AM1.5G) V oc = 909 mv J sc = 16.5 ma/cm 2 FF = 42.9 % Eff. = 6.5 % p: PEDOT:PSS, MoOx, P3HT, Spiro- MeOTAD n: ZnO, TiOx, PCBM. -15-20 -0.2-0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Voltage (V)

External Quantum Efficiency Tandem solar cell: Perovskite and a-si:h/c-si Heterojunction Current (ma/cm 2 ) Schematic cross section of the tandem solar cells under investigation 16 12 8 Sample #1 12/2014 J sc = 10.4 ma/cm 2 4 V oc = 1.641 V FF = 50.4% Eff = 8.6% 0 0.0 0.4 0.8 1.2 1.6 Voltage (V) Experimental J-V characteristics of tandem cells a) Sample #2 5/2015 J sc = 16.1 ma/cm 2 V oc = 1.635 V FF = 54.4% Eff = 14.3% 1.0 0.8 0.6 0.4 0.2 0.0 Glass FTO compact-tio 2 porous TiO 2 Perovskite Spiro-OMeTAD ITO n-a-si:h i-a-si:h p-c-si BRAGG Al b) Sample #1 12/2014{ Sample #2 5/2015 { Center for Hybrid and Organic Solar Energy Top #1 Bottom #1 Top #2 Bottom #2 400 600 800 1000 1200 Wavelength (nm) Experimental External Quantum Efficiency of the tandem cell I S P T I p i- n A A

Partners Università di Genova Dipartimento di Fisica Università del Sannio - Dipartimento di Ingegneria Università di Napoli Federico II Dipartimento di Ingegneria dei Materiali e della Produzione Università di Napoli Federico II - Dipartimento di Ingegneria Elettrica e delle Tecnologie dell Informazione Università di Napoli Federico II Dipartimento di Chimica Università di Modena e Reggio Emilia - Dipartimento di Chimica Università di Napoli Federico II Dipartimento di Fisica Università di Trento - Dipartimento di Ingegneria dei Materiali e Tecnologie Industriali Università La Sapienza di Roma - Dipartimento di Fisica Università La Sapienza di Roma - Dipartimento di Ingegneria Elettrica e delle Tecnologie dell Informazione Università di Milano Bicocca - Dipartimento di Scienze dei Materiali