Discovery of the Zintl-phosphide BaCd${}_2$P${}_2$ as a long carrier lifetime and stable solar absorber

Abstract

Thin-film photovoltaics offers a path to significantly decarbonize our energy production. Unfortunately, current materials commercialized or under development as thin-film solar cell absorbers are far from optimal as they show either low power conversion efficiency or issues with earth-abundance and stability. Entirely new and disruptive materials platforms are rarely discovered as the search for new solar absorbers is traditionally slow and serendipitous. Here, we use first principles high-throughput screening to accelerate this process. We identify new solar absorbers among known inorganic compounds using considerations on band gap, carrier transport, optical absorption but also on intrinsic defects which can strongly limit the carrier lifetime and ultimately the solar cell efficiency. Screening about 40,000 materials, we discover the Zintl-phosphide BaCd${}_2$P${}_2$ as a potential high-efficiency solar absorber. Follow-up experimental work confirms the predicted promises of BaCd${}_2$P${}_2$ highlighting an optimal band gap for visible absorption, bright photoluminescence, and long carrier lifetime of up to 30 ns even for unoptimized powder samples. Importantly, BaCd${}_2$P${}_2$ does not contain any critical elements and is highly stable in air and water. Our work opens an avenue for a new family of stable, earth-abundant, high-performance Zintl-based solar absorbers. It also demonstrates how recent advances in first principles computation can accelerate the search of photovoltaic materials by combining high-throughput screening with experiment.

References in corpus (11)

• Design of Lead-Free Inorganic Halide Perovskites for Solar Cells via Cation-Transmutation
• Identifying defect-tolerant semiconductors with high minority carrier lifetimes: Beyond hybrid lead halide perovskites
• Efficient calculation of carrier scattering rates from first principles
• First-principles theory of nonradiative carrier capture via multiphonon emission
• A precisely regulating phase evolution strategy for highly efficient kesterite solar cells
• Perovskite-Inspired Materials for Photovoltaics -- From Design to Devices
• Upper limit to the photovoltaic efficiency of imperfect crystals
• Rapid Recombination by Cadmium Vacancies in CdTe
• Quantifying Charge Carrier Mobilities and Recombination Rates in Metal Halide Perovskites from Time-Resolved Microwave Photo-conductivity Measurements
• Stoichiometric Control and Optical Properties of BaTiO3 Thin Films Grown by Hybrid MBE
• First-principles study of intrinsic and hydrogen point defects in the earth-abundant photovoltaic absorber Zn3P2

Cited by in corpus (4)

• doped: Python toolkit for robust and repeatable charged defect supercell calculations
• Assessing carrier mobility, dopability, and defect tolerance in the chalcogenide perovskite BaZrS${}_3$
• A Map of the Zintl AM2Pn2 Compounds: Influence of Chemistry on Stability and Electronic Structure
• CaCd${}_2$P${}_2$: A Visible-Light Absorbing Zintl Phosphide Stable under Photoelectrochemical Water Oxidation