Combinatorial Separation of Cd and Te from CdTe via Chemical Vapour Transport with Sulfur and Air/Methane Treatment for the Recovery of Critical Resources from Thin Film Solar Cells.

Elemental Te and Cd are successfully recovered from CdTe via a combinatorial process involving chemical vapor transport (CVT) using sulfur as transport agent giving elemental Te being deposited. Separation is successfully enabled by the first process for CVT of Te starting with CdTe. Cd is subsequently recovered by an oxidation of the formed CdS to CdO followed by reduction to Cd metal with natural gas, in which Cd can also be separated via the gas phase. Hereby, the process addresses the main critical elements of the active material in thin film CdTe solar cells regarding both, scarcity and toxicity. Both, closed and open systems were investigated displaying more or less thermodynamic control of the system. Transport rates were determined for the closed system as well as for an open system working with sulfur vapour at moderate temperatures below and close to the boiling point of sulfur. Excellent purity of tellurium was achieved already by the initial transport, leading to low Cd2+ concentrations in the obtained Te being below the quantification limit of microwave plasma-atomic emission spectroscopy (MP-AES) (≪0.05 wt %).

High Open-Circuit Voltage Cs2 AgBiBr6 Carbon-Based Perovskite Solar Cells via Green Processing of Ultrasonic Spray-Coated Carbon Electrodes from Waste Tire Sources.

Invited for this month cover is the group of Teresa Gatti at the Justus Liebig University (JLU) in Giessen, Germany, the group of Federico Bella at Politecnico di Torino (POLITO), Italy, and the group of Francesco Lamberti at the University of Padova (UNIPD), also in Italy. The image shows how waste tires can be converted in a conductive carbon powder that undergoes a green processing step to produce carbon electrodes for lead-free perovskite solar cells. Similar devices can be employed to harvest indoor light in order to power the Internet of Things (IoT) ecosystem. The Research Article itself is available at 10.1002/cssc.202201590.

High Open-Circuit Voltage Cs2 AgBiBr6 Carbon-Based Perovskite Solar Cells via Green Processing of Ultrasonic Spray-Coated Carbon Electrodes from Waste Tire Sources.

Costs and toxicity concerns are at the center of a heated debate regarding the implementation of perovskite solar cells (PSCs) into commercial products. The first bottleneck could be overcome by eliminating the top metal electrode (generally gold) and the underlying hole transporting material and substituting both with one single thick layer of conductive carbon, as in the so-called carbon-based PSCs (C-PSCs). The second issue, related to the presence of lead, can be tackled by resorting to other perovskite structures based on less toxic metallic components. An interesting case is that of the double perovskite Cs2 AgBiBr6 , which at present still lacks the outstanding optoelectronic performances of the lead-based counterparts but is very stable to environmental factors. In this work, the processing of carbon electrodes onto Cs2 AgBiBr6 -based C-PSCs was reported, starting from an additive-free isopropanol ink of a carbon material obtained from the hydrothermal recycling of waste tires and employing a high-throughput ultrasonic spray coating method in normal environmental conditions. Through this highly sustainable approach that ensures a valuable step from an end-of-life to an end-of-waste status for used tires, devices were obtained delivering a record open circuit voltage of 1.293 V, which might in the future represent ultra-cheap solutions to power the indoor Internet of Things ecosystem.