Atomically thin interlayer phase from first principles enables defect-free incommensurate SnO2/CdTe interface

Sharan, Abhishek (ORCID:0000000263942199); Nardone, Marco (ORCID:000000034410623X); Krasikov, Dmitry (ORCID:0000000270909418); Singh, Nirpendra (ORCID:0000000180430403); Lany, Stephan (ORCID:0000000281278885)

doi:10.1063/5.0104008

DOE OSTI · 2564527

Atomically thin interlayer phase from first principles enables defect-free incommensurate SnO2/CdTe interface

Sharan, Abhishek (ORCID:0000000263942199)·Nardone, Marco (ORCID:000000034410623X)·Krasikov, Dmitry (ORCID:0000000270909418)·Singh, Nirpendra (ORCID:0000000180430403)·Lany, Stephan (ORCID:0000000281278885)

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Abstract

Advancing optoelectronic and emerging technologies increasingly requires control and design of interfaces between dissimilar materials. However, incommensurate interfaces are notoriously defective and rarely benefit from first-principles predictions, because no explicit atomic-structure models exist. Here, we adopt a bulk crystal structure prediction method to the interface geometry and apply it to SnO2/CdTe heterojunctions without and with the addition of CdCl2, a ubiquitous and beneficial, but abstruse processing step in CdTe photovoltaics. Whereas the direct SnO2/CdTe interface is highly defective, we discover a unique two-dimensional CdCl2 interphase, unrelated to the respective bulk structure. It facilitates a seamless transition from the rutile to zincblende lattices and removes defect-states from the interface bandgap. Implementing the predicted interface electronic structure in device simulations, we demonstrate the theoretical feasibility of bufferless oxide-CdTe heterojunction solar cells approaching the Shockley–Queisser limit. Our results highlight the broader potential of designing atomically thin interlayers to enable defect-free incommensurate interfaces.

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14 SOLAR ENERGY 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS CdTe crystal structure prediction device simulation electronic structure first principles calculation interfaces

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Sharan, Abhishek (ORCID:0000000263942199), Nardone, Marco (ORCID:000000034410623X), Krasikov, Dmitry (ORCID:0000000270909418), Singh, Nirpendra (ORCID:0000000180430403), Lany, Stephan (ORCID:0000000281278885). 2022-12-05. Atomically thin interlayer phase from first principles enables defect-free incommensurate SnO2/CdTe interface. https://doi.org/10.1063/5.0104008

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