CAREER: Developing solution-based thin-film chalcogenide perovskites

NON-TECHNICAL SUMMARY

Photovoltaics are a renewable and clean source of energy which are rapidly becoming one of the cheapest forms of energy available in the US. However, many key scientific advancements are still needed to achieve widespread adoption of photovoltaic technology. This includes discovering and developing new photovoltaic materials and better understanding and controlling their properties.

This NSF CAREER award project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, aims to develop a new class of materials – chalcogenide perovskites – for low-cost, non-toxic, and stable photovoltaics which can replace existing technologies due to their improved properties. Several challenges limit experimental progress for this material.

To overcome these, novel techniques developed by Prof. Charles Hages’ research group at the University of Florida are used to synthesize these new materials. This includes the use of extremely small (nanoscale) building blocks to uniquely control material assembly.

Experimental work is guided by theoretical work to identify previously unrealized promising materials whose properties are measured through advanced characterization techniques. Integrated with this research is a cross-generational STEM education and outreach plan targeting the underserved local community. This includes (1) a tailored STEM education program in renewable energy for the aging population at local independent- and assisted-living communities, and (2) K-12 education and youth programs in climate change and renewable energy education.

The outcomes of this educational plan are: to enhance the perception of the value of science & technology to society, the role of academia, and the value of public funding for these pursuits; to increase public engagement with science and technology; and to enhance scientific literacy, particularly among underrepresented communities.

TECHNICAL SUMMARY

This NSF CAREER award project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, establishes a new solution-based synthesis for chalcogenide perovskites and experimentally realizes new chalcogenide perovskite compounds with desirable optoelectronic properties for photovoltaics. Chalcogenide perovskites are an emerging class of semiconductor with the potential to replace the ubiquitous organic-inorganic hybrid metal halide perovskites as a high-performance photovoltaic absorber.

This is a result of their predicted enhanced stability, favorable charge transport and absorption properties, and non-toxic nature – while maintaining the defect tolerance and high optoelectronic tunability typical of perovskites. However, minimal experimental research is reported in this field, resulting in a significant theory experiment knowledge gap.

Furthermore, the reported high-temperature syntheses with long reaction times significantly limits their amenability to tunable materials chemistry for controlling their material properties and synthesis into thin films. To address this, Prof. Charles Hages’ research group at the University of Florida pursues research along three specific aims.

Aim 1 establishes a new synthesis for thin-film chalcogenide perovskites by reactive annealing of metastable solution-based nanoparticle precursors. Aim 2 proposes a new phase stability analysis for this material space and rationalizes a focus in several previously unrealized selenium-based chalcogenide perovskites. Aim 3 proposes an all-optical characterization strategy to map the synthesis-structure-property relationship of these new compounds.

This research is integrated with cross-generational STEM education and outreach in renewable energy, which includes developing and delivering tailored educational modules for the underserved local aging community and K-12 students. Research is also integrated with training and education for graduate and undergraduate students in teaching, technical communication, and in emerging energy technologies.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.