arXiv subjects

Leandro Silva Herculano

Publications and source records attributed to Leandro Silva Herculano.

3 recordsLinked to original sources

arXiv2022

Towards long term sustainability of c-Si solar panels: the environmental benefits of glass sheet recovery

The cover glass in a silicon solar panel accounts for about 2/3 of the device's weight. Recycling these devices at their end-of-life is fundamental to reducing the industry's environmental impact. Here we investigate the recovery of these glass sheets by a heat-assisted mechanical process. A panel was delaminated, and we have utilized Fourier-transform infrared, Raman, and energy-dispersive spectroscopies to confirm the composition of the remaining components and identify aging signals. The results demonstrate that the panel's design was similar to most Silicon solar panels in the market, and we concluded that it would be feasible to recover the glass in most of these devices. Due to its chemical and mechanical strength, this glass would be ready to be reused without the need to melt it again, bringing substantial savings in its energy content and carbon emission related to its production. The glass sheet would be ready to be used as cover glass in another solar panel or architecture material. Our estimates showed that this could be a pathway to reducing the photovoltaic industry's carbon emissions by more than 2 million tonnes per year.

cond-mat.mtrl-sci↗

arXiv2021

Float, borosilicate and tellurites as cover glasses in Si photovoltaics: optical properties and performances under sunlight

One of the most significant materials in a solar panel is the glass, which provides transparency, UV protection as well as mechanical and chemical resistance. In this work, we describe the production of prototypes of four solar modules made using borosilicate, zinc-tellurite, Pr$^{3+}$ doped zinc-tellurite, and float glass as cover materials. The performance of these prototypes was evaluated under a solar simulator, and a device was developed to monitor all prototypes under real conditions. A comparison between indoor and outdoor measurements shows that outdoor results are fundamental to evaluate the performance of modified solar modules as the ones considered in this study. In addition, we demonstrate the fundamental role played by the refractive index of cover glasses in the performance of the prototypes, and discuss how this feature could be explored to achieve enhanced devices, as well as other benefits that may arise from this field of research.

cond-mat.mtrl-sci↗

arXiv2018

On the prospects of enhance glass based devices with silver nanoparticles: the case of Pr3+ doped tellurite-tungstate glasses

The development of enhanced optical devices relies on key materials properties. In this context, researchers have investigated the effects of metal nanoparticles incorporation in active rare-earth materials. Here, we discuss the effects of Silver nitrate addition 0.5%, 1.0% and 2.0% mol%) into a Pr3+ doped tellurite-tungstate glasses (TWNN) formed by the conventional melt-quenching technique. The XRD curves confirmed the amorphous structural nature of TWNN glasses. The FTIR spectra identified the presence of different vibrational groups. DSC curves verified the increase around 70 oC for thermal stability with silver addition. Absorption spectra observed surface plasmon resonance (SPR) band around 500 nm. Luminescence measures shows enhanced and quenching for Pr3+ transitions under the 473 nm excitation. The band around 480-520 nm are more affected by SPR band by quenching, and the bands around 575-675 nm are luminescence emission increased due to the presence of silver nanoparticles. In addition, lifetime decays as a function of heat treatment time, has also been verified. The Ag enhances the lifetime regarding the samples annealed by 20 hours and as the Ag concentration increases, the lifetime stretches as well. The present results shows that Pr3+-Ag codoped TWNN glass lead to some remarkable improvement, verified in properties such as lifetime constants or emissions intensities and is a promising candidate for photonic devices.

cond-mat.mtrl-sci↗