Determining the Cost of Organic Photovoltaic Material and Its Impact on the Levelized Cost of Electricity

Abstract The field of organic photovoltaics (OPV) has delivered significant performance increases through the development of donor polymers and non-fullerene acceptors (NFAs). However, these improvements have come at the expense of increased synthetic complexity, reduced scalability, and consequently higher cost. By contrast, the development of commercial OPV technology requires scalable donor–acceptor materials, which can achieve a competitive levelized cost of electricity (LCOE). As such, if OPV technology is to become commercially viable, synthetic accessibility, quantification of cost, and active layer contribution to LCOE need to be considered. This paper presents three case studies examining the cost of materials (COM) for two polymer donors (poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4,5-b′]dithiophene))-alt-(5,5-(1′,3′-di-2-thienyl-5′,7′-bis(2-ethylhexyl)benzo[1′,2′-c:4′,5′-c′]dithiophene-4,8-dione))] (PBDB-T) and poly[2,2⁗-bis[[(2-butyloctyl)oxy]carbonyl][2,2′:5′,2″:5″,2‴-quaterthiophene]-5,5‴-diyl] (PDCBT)), and one non-fullerene acceptor (NFA) (3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]dithiophene (ITIC)). Published synthesis procedures for these materials were investigated to determine laboratory-scale COM. This analysis revealed that the NFA was significantly more expensive (~five-fold) than the cheapest donor material. Consequently, the ITIC synthesis was experimentally optimized (ITIC-Exp), delivering a significant (~six-fold) reduction in COM. Finally, bulk-scale COM was calculated based on established cost scaling laws for speciality chemicals. The effect of laboratory- and bulk-scale COM upon the LCOE for OPV modules printed at commercial scale was determined. This work highlights the finding that, at laboratory scale, a COM of $60 g −1 represents a reasonable active layer cost benchmark for competitive LCOE. This study further reveals that at bulk scale, a highly competitive LCOE ($0.13–$0.08) is achievable for the optimal donor–acceptor pair (PDCBT-DArP:ITIC-Exp) at modest efficiency (3–5%) and lifetime (3–5 years).