First-principles study of lead-free Ge-based 2D Ruddlesden-Popper hybrid perovskites for solar cell applications.
Phys Chem Chem Phys
; 24(35): 21052-21060, 2022 Sep 14.
Article
en En
| MEDLINE
| ID: mdl-36004762
ABSTRACT
Recently, 2D halide perovskites have attracted attention because they are excellent photo absorbing materials for perovskite solar cells. To date, the majority of 2D perovskite-based devices have been made of Pb, a material with toxic properties and environmental concerns. Thus, lead-free alternatives are essential to enable the expansion of photovoltaic systems based on perovskites. Herein, we examine the structural, electronic, optical and stability properties of Pb-free 2D Ruddlesden-Popper (RP) perovskites (BA)2(MA)n-1GenI3n+1 (BA = CH3(CH2)3NH3+; MA = CH3NH3+; n = 1-5, and â) by using DFT calculations and comparing the results to their Pb-based counterparts (BA)2(MA)n-1PbnI3n+1 (n = 1-5, and â). Theoretical analysis indicates that Pb and Ge-based 2D perovskites are significantly more thermodynamically stable than their corresponding 3D materials. A more accurate bandgap is achieved using the HSE06 + SOC scheme and compared to the findings of the PBE and PBE + SOC. These materials are direct bandgap semiconductors. Due to spin-orbit coupling, Pb-based perovskite displays higher Rashba energy splitting than Ge-based ones. The bandgap changes from 2.37 eV (n = 1) to 1.79 eV (n = 5), and from 1.92 eV (n = 1) to 1.56 eV (n = 5) for Pb and Ge-based perovskites, respectively. The bandgap of all Ge-based perovskites is lower than their corresponding Pb-based ones. We show that the 2D perovskites could serve as hole-transporting materials when they are alongside 3D perovskites. The trade-off between thermodynamic stability and absorption coefficient of the considered compounds indicates that 2D RP perovskites BA2MA4Ge5I16 are promising Pb-free halide semiconductors for solar cell applications.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
Phys Chem Chem Phys
Asunto de la revista:
BIOFISICA
/
QUIMICA
Año:
2022
Tipo del documento:
Article
País de afiliación:
Irán