Assessing Carrier Mobility, Dopability, and Defect Tolerance in the Chalcogenide Perovskite <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>Ba</mml:mi> <mml:mi>Zr</mml:mi> <mml:mi mathvariant="normal">S</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> </mml:msub> </mml:math>

Abstract

The chalcogenide perovskite <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <a:msub> <a:mrow> <a:mi>Ba</a:mi> <a:mi>Zr</a:mi> <a:mi mathvariant="normal">S</a:mi> </a:mrow> <a:mn>3</a:mn> </a:msub> </a:math> has attracted much attention as a promising solar absorber for thin-film photovoltaics. Here we use first-principles calculations to evaluate its carrier transport and defect properties. We find that <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <e:msub> <e:mrow> <e:mi>Ba</e:mi> <e:mi>Zr</e:mi> <e:mi mathvariant="normal">S</e:mi> </e:mrow> <e:mn>3</e:mn> </e:msub> </e:math> has a phonon-limited electron mobility of <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <i:mn>37</i:mn> <i:mspace width="0.2em"/> <i:msup> <i:mi>cm</i:mi> <i:mn>2</i:mn> </i:msup> <i:mo>/</i:mo> </i:math> V s, which is comparable to that in halide perovskites, but lower hole mobility of <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <m:mn>11</m:mn> <m:mspace width="0.2em"/> <m:msup> <m:mi>cm</m:mi> <m:mn>2</m:mn> </m:msup> <m:mo>/</m:mo> </m:math> V s. The defect computations indicate that <q:math xmlns:q="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <q:msub> <q:mrow> <q:mi>Ba</q:mi> <q:mi>Zr</q:mi> <q:mi mathvariant="normal">S</q:mi> </q:mrow> <q:mn>3</q:mn> </q:msub> </q:math> is intrinsically <u:math xmlns:u="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <u:mi>n</u:mi> </u:math> -type due to shallow sulfur vacancies, but that strong compensation by sulfur vacancies will prevent attempts to make it <x:math xmlns:x="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <x:mi>p</x:mi> </x:math> -type. We also establish that <ab:math xmlns:ab="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <ab:msub> <ab:mrow> <ab:mi>Ba</ab:mi> <ab:mi>Zr</ab:mi> <ab:mi mathvariant="normal">S</ab:mi> </ab:mrow> <ab:mn>3</ab:mn> </ab:msub> </ab:math> shows some degree of defect tolerance, presenting only few low formation energy, deep intrinsic defects. Among the deep defects, sulfur interstitials are the dominant nonradiative recombination centers but exhibit a moderate capture coefficient. Our work highlights the material’s intrinsic limitations in carrier mobility and <eb:math xmlns:eb="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <eb:mi>p</eb:mi> </eb:math> -type doping, and suggests focusing on suppressing the formation of sulfur interstitials to achieve longer carrier lifetime. Published by the American Physical Society 2024

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