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Title: Composite Nature of Layered Hybrid Perovskites: Assessment on Quantum and Dielectric Confinements and Band Alignment

Layered hybrid organic–inorganic perovskites (HOPs) have re-emerged as potential technological solutions for next-generation photovoltaic and optoelectronic applications. Their two-dimensional (2D) nature confers them a significant flexibility and results in the appearance of quantum and dielectric confinements. Such confinements are at the origin of their fascinating properties, and understanding them from a fundamental level is of paramount importance for optimization. Here, we provide an in-depth investigation of band alignments of 2D HOP allowing access to carriers’ confinement potentials. 2D HOPs are conceptualized as composite materials in which pseudoinorganic and -organic components are defined. In this way, computational modeling of band alignments becomes affordable using first-principles methods. First, we show that the composite approach is suitable to study the position-dependent dielectric profiles and enables clear differentiation of the respective contributions of inorganic and organic components. Then we apply the composite approach to a variety of 2D HOPs, assessing the impact on the confinement potentials of well and barrier thickness, of the nature of the inorganic well, and of structural transitions. Using the deduced potentials, we further discuss the limitations of the effective mass approximation, scrutinizing the electronic properties of this family of composite materials. Our simulations demonstrate type-I dominant band alignment inmore » 2D HOPs. Finally, we outline design principles on band alignment toward achieving specific optoelectronic properties. Furthermore, we present alternative theoretical methods to inspect the properties of 2D hybrid perovskites and expect that the composite approach will be applicable to other classes of layered materials.« less
Authors:
ORCiD logo [1] ; ORCiD logo [1] ;  [2] ;  [1] ; ORCiD logo [3] ;  [3] ; ORCiD logo [3] ; ORCiD logo [4] ; ORCiD logo [4] ; ORCiD logo [3] ; ORCiD logo [3] ; ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [1]
  1. Univ. Rennes, Rennes (France)
  2. Univ. Rennes, Rennes (France); TOTAL SA, Courbevoie (France)
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  4. Northwestern Univ., Evanston, IL (United States)
Publication Date:
Report Number(s):
LA-UR-18-20159
Journal ID: ISSN 1936-0851
Grant/Contract Number:
AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
ACS Nano
Additional Journal Information:
Journal Volume: 12; Journal Issue: 4; Journal ID: ISSN 1936-0851
Publisher:
American Chemical Society (ACS)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Material Science; Perovskite, theory, quantum and dielectric confinement
OSTI Identifier:
1440494