Perovskite materials research has received unprecedented recognition due to its applications in photovoltaics, LEDs, and other large area low-cost electronics. The exceptional improvement in the photovoltaic conversion efficiency of Perovskite solar cells (PSCs) achieved over the last decade has prompted efforts to develop and optimize device fabrication technologies for the industrial and commercial space. However, unstable operation in outdoor environments and toxicity of the employed materials and solvents have hindered this proposition. While their optoelectronic properties are extensively studied, the environmental impacts of the materials and manufacturing methods require further attention. This review summarizes and discusses green and environment-friendly methods for fabricating PSCs, particularly non-toxic solvents, and lead-free alternatives. Greener solvent choices are surveyed for all the solar cell films, (i.e. electron and hole transport, semiconductor, and electrode layers) and their impact on thin film quality, morphology and device performance is explored. We also discuss lead content in perovskites, its environmental impact and sequestration routes, and progress in replacing lead with greener alternatives. This review provides an analysis of sustainable green routes in perovskite solar cell fabrication, discussing the impact of each layer in the device stack, via life cycle analysis.
Micellar catalysis enables carrying out Suzuki–Miyaura couplings in water under exceptionally mild conditions. Extension of such a protocol to the sustainable synthesis of highly conjugated, poorly soluble materials like [1]benzothieno[3,2-b][1]benzothiophene (BTBT) requires redesigning of the surfactants employed. The here reported new naphthalenediimide containing amphiphilic derivative, PiNap-750M, features unprecedented performances in the preparation of this and other relevant classes of organic semiconductors in water and at room temperature.
Conjugated semiconducting polymers are key materials enabling plastic (opto)electronic devices. Research in the field has a generally strong focus on the constant improvement of backbone structure and the resulting properties. Comparatively fewer studies are devoted to improving the sustainability of the synthetic route that leads to a material under scrutiny. Exemplified by the two established and commercially available luminescent polymers poly(9,9-dioctylfluorene-alt-bithiophene) (PF8T2) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (PF8BT), this work describes the first examples of efficient Suzuki-Miyaura polycondensations in water, under ambient environment, with minimal amount of organic solvent and with moderate heating. The synthetic approach enables a reduction of the E-factor (mass of organic waste/mass of product) by 1 order of magnitude, without negatively affecting molecular weight, dispersity, chemical structure, or photochemical stability of PF8T2 or PF8BT.