Economical eco-friendly manufacture of high efficiency chalcopyrite solar cells

• Clean, lasting energy options are essential to fulfill the ever-increasing energy demands of the human population. High efficiency solar cells are promising candidates to reduce carbon emissions as well as achieve carbon neutrality.

In this regard, solution-processed copper indium gallium sulfur diselenide solar cells (CIGSSe) solar cells have actually produced significant interest owing to their outstanding solar residential or commercial properties, such as high absorption of visible light, stability, and tunable bandgap.

However, huge scale, functional applications are limited by a two-fold challenge. Firstly, solution-based CIGSSe construction yields really reduced power conversion efficiency as well as often utilizes solvents that are not environment-friendly. Secondly, to achieve higher power conversion efficiency, manufacture methods rely on pricey vacuum environment that causes substantial product loss.

To this end, a group of researchers led by Professor JunHo Kim from Global Energy Research Center for Carbon Neutrality, Incheon National University, Korea have created a low-priced and also eco-friendly construction method of high efficiency CIGSSe solar cells.

In a research study published in Advanced Functional Materials, the scientists utilized aqueous spray deposition in an air environment and developed a CIGSSe solar cell with power conversion efficiency (PCE) larger than 17 %.

" For spray service, we used deionized water, which is eco-friendly as well as cheapest solvent till date," explains Prof. Kim. Moreover, standard solution-based manufacture processes rely on ecologically dangerous, cadmium-based buffers for the optimization of thin-film solar cells. In this unique technique, the scientists made use of indium sulfide-based buffer that is a cadmium cost-free, eco-friendly choice.

The scientists additionally checked out the alloying impacts of zirconium on indium sulfide buffers. Remarkably, the team located that zirconium alloying boosts the electron concentration in the buffer. Furthermore, this method "passivates" or lowers defect states in the CIGSSe absorber, enhancing the charge transfer in between various interfaces, resulting in enhanced PCE.

Additionally, the scientists achieved a lot more defect passivation as well as greater PCE, of more than 17%, by alloying the CIGSSe absorber with potassium. The made cell has an optimum bandgap for high efficiency applications such as a bottom cell or a tandem cell.

This unique technique is cost-effective as well as conveniently scalable as it does not require a vacuum environment. As Prof. Kim observes, "We performed spray deposition in an air environment without utilizing any high vacuum facility, which significantly lowers construction cost and also thus makes the fabrication technique more practical and competitive in the market sector."

This development concurrently boosts the performance and construction of CIGSSe solar cells. This will revolutionize the application of these cells in integrated photovoltaic devices and lorry incorporated photovoltaic or pv devices, and as energy sources for internet of things devices.