• Energy Research

The transition toward circular economy models has been progressively promoted in the last few years. Different disciplines and strategies may significantly support this change. Although the specific contribution derived from design, material science, and additive manufacturing is well-established, their interdisciplinary relationship in circular economy contexts is relatively unexplored. This paper aims to review the main case studies related to new circular economy models for waste valorization through extrusion-based additive manufacturing, circular materials, and new design strategies. The general patterns were investigated through a comprehensive analysis of 74 case studies from academic research and design practice in the last six-year period (2015–2021), focusing on the application fields, the 3D printing technologies, and the materials. Further considerations and future trends were then included by looking at the relevant funded projects and case studies of 2021. A broader number of applications, circular materials, and technologies were explored by the academic context, concerning the practice-based scenario linked to more consolidated fields. Thanks to the development of new strategies and experiential tools, academic research and practice can be linked to foster new opportunities to implement circular economy models.

The transition toward circular economy models has been progressively promoted in the last few years. Different disciplines and strategies may significantly support this change. Although the specific contribution derived from design, material science, and additive manufacturing is well-established, their interdisciplinary relationship in circular economy contexts is relatively unexplored. This paper aims to review the main case studies related to new circular economy models for waste valorization through extrusion-based additive manufacturing, circular materials, and new design strategies. The general patterns were investigated through a comprehensive analysis of 74 case studies from academic research and design practice in the last six-year period (2015–2021), focusing on the application fields, the 3D printing technologies, and the materials. Further considerations and future trends were then included by looking at the relevant funded projects and case studies of 2021. A broader number of applications, circular materials, and technologies were explored by the academic context, concerning the practice-based scenario linked to more consolidated fields. Thanks to the development of new strategies and experiential tools, academic research and practice can be linked to foster new opportunities to implement circular economy models.

The solution-based deposition of the metal back electrode in inverted polymer solar cells (PSCs) using roll-to-roll (R2R) compatible processing technologies is considered one of the crucial issues towards the upscaling of PSC technology, as it may allow the full exploitation of the high through-put and prospective low-costs envisaged by the R2R fabrication approach. In this work, a water-based solution-processable silver ink formulation with low annealing temperature was developed to be used as precursor for the fabrication of the metallic back-electrode in flexible inverted PSC devices fabricated by means of R2R-compatible printing techniques. In order to investigate the effect of the deposition of such reactive silver ink on the underlying PSC layers, different back-electrode architectures were investigated and thoroughly characterized. In addition, the influence of the thickness of the hole-transporting poly(ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) buffer layer on the functional performance of the PSC devices was also investigated and an optimized combination of back-electrode architecture and PEDOT:PSS thickness was found, that also allowed to obtain semi-transparent PSC devices. The results of this study demonstrate the possibility to employ R2R-compatible processing techniques for the deposition of the metallic back-electrode in flexible inverted PSCs from a solution-processable water-based reactive silver ink formulation characterized by low-annealing temperature, and provide useful insights into the key role played by the hole-transporting buffer layer in the realization of fully functional flexible PSC devices.

The solution-based deposition of the metal back electrode in inverted polymer solar cells (PSCs) using roll-to-roll (R2R) compatible processing technologies is considered one of the crucial issues towards the upscaling of PSC technology, as it may allow the full exploitation of the high through-put and prospective low-costs envisaged by the R2R fabrication approach. In this work, a water-based solution-processable silver ink formulation with low annealing temperature was developed to be used as precursor for the fabrication of the metallic back-electrode in flexible inverted PSC devices fabricated by means of R2R-compatible printing techniques. In order to investigate the effect of the deposition of such reactive silver ink on the underlying PSC layers, different back-electrode architectures were investigated and thoroughly characterized. In addition, the influence of the thickness of the hole-transporting poly(ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) buffer layer on the functional performance of the PSC devices was also investigated and an optimized combination of back-electrode architecture and PEDOT:PSS thickness was found, that also allowed to obtain semi-transparent PSC devices. The results of this study demonstrate the possibility to employ R2R-compatible processing techniques for the deposition of the metallic back-electrode in flexible inverted PSCs from a solution-processable water-based reactive silver ink formulation characterized by low-annealing temperature, and provide useful insights into the key role played by the hole-transporting buffer layer in the realization of fully functional flexible PSC devices.

In the present paper the electroless metallization of 3D printed parts using stereolithography is investigated. Two different photocurable resins of large commercial diffusion and a self-formulated one are used as starting materials for printing. A first metal layer of NiP or Cu, obtained by an optimized pretreatment and plating process, is subsequently applied on the parts. It is also demonstrated the possibility of obtaining multilayers through the successive electrodeposition of different metals on the electroless treated parts. The resulting layers are characterized by SEM and profilometry.

In the present paper the electroless metallization of 3D printed parts using stereolithography is investigated. Two different photocurable resins of large commercial diffusion and a self-formulated one are used as starting materials for printing. A first metal layer of NiP or Cu, obtained by an optimized pretreatment and plating process, is subsequently applied on the parts. It is also demonstrated the possibility of obtaining multilayers through the successive electrodeposition of different metals on the electroless treated parts. The resulting layers are characterized by SEM and profilometry.

Abstract A study on the effect of different device parameters on the photophysical and photovoltaic behavior of thin-film luminescent solar concentrators (LSCs) is presented in this work. The concentration of the luminescent species, the thickness of the LSC film, the geometric gain of the LSC device and the composition and thickness of the white back reflector are systematically varied and their influence on LSC thin film properties and device performance is examined. It is shown that dye concentration and LSC film thickness have a major effect on the optical response of the LSC devices. The efficiency is found to decrease with increasing geometric gain, although saturation is observed for high geometric gains suggesting that LSC devices perform best for very large LSC areas. The surface roughness of the back reflector is found to play a key role in improving the efficiency of the LSC film because it induces a reduction of specular reflectivity and an increase of isotropic light scattering. The results of this study allow a greater understanding of the relationships between key LSC device parameters and the photophysical and photovoltaic behavior of planar thin-film LSC systems and provide useful guidelines for optimal design of thin-film LSC devices.

Abstract A study on the effect of different device parameters on the photophysical and photovoltaic behavior of thin-film luminescent solar concentrators (LSCs) is presented in this work. The concentration of the luminescent species, the thickness of the LSC film, the geometric gain of the LSC device and the composition and thickness of the white back reflector are systematically varied and their influence on LSC thin film properties and device performance is examined. It is shown that dye concentration and LSC film thickness have a major effect on the optical response of the LSC devices. The efficiency is found to decrease with increasing geometric gain, although saturation is observed for high geometric gains suggesting that LSC devices perform best for very large LSC areas. The surface roughness of the back reflector is found to play a key role in improving the efficiency of the LSC film because it induces a reduction of specular reflectivity and an increase of isotropic light scattering. The results of this study allow a greater understanding of the relationships between key LSC device parameters and the photophysical and photovoltaic behavior of planar thin-film LSC systems and provide useful guidelines for optimal design of thin-film LSC devices.