The role of lattice mismatch on the emergence of surface states in 2D hybrid perovskite quantum wells

Abstract

Surface states are ubiquitous to semiconductors and significantly impact the physical properties and consequently the performance of optoelectronic devices. Moreover, surface effects are strongly amplified in lower dimensional systems such as quantum wells and nanostructures. Layered halide perovskites (LHPs) are 2D solution-processed natural quantum wells, where optoelectronic properties can be tuned by varying the perovskite layer thickness. They are efficient semiconductors with technologically relevant stability. Here, a generic elastic model and electronic structure modelling are applied to LHPs heterostructures with various layer thickness. We show that the relaxation of the interface strain is triggered by perovskite layers above a critical thickness. This leads to the release of the mechanical energy arising from the lattice mismatch, which nucleates the surface reorganization and consequently the formation of lower energy edge states. These states, which are absent in 3D perovskites, dominate the optoelectronic properties of LHPs and are anticipated to play a crucial role in the design of LHPs for optoelectronics devices.

References in corpus (7)

• The SIESTA method for ab initio order-N materials simulation
• Efficient index handling of multidimensional periodic boundary conditions
• Van der Waals Density Functional for General Geometries
• Silicon Quantum Electronics
• Linear-scaling ab-initio calculations for large and complex systems
• Van der Waals density functional: an appropriate exchange functional
• Unusual thickness dependence of exciton characteristics in 2D perovskite quantum wells

Cited by in corpus (4)

• Bright Luminescent Surface States on the Edges of Wide-bandgap Two-dimensional Lead Halide Perovskite
• Self-formed 2D/3D Heterostructure on the Edge of 2D Ruddlesden-Popper Hybrid Perovskites Responsible for Intriguing Optoelectronic Properties and Higher Cell Efficiency
• Layer Edge States Stabilized by Internal Electric Fields in Two-dimensional Hybrid Perovskites
• Tailoring Photoluminescence by Strain-Engineering in Layered Perovskite Flakes