Unlocking the Single‐Domain Epitaxy of Halide Perovskites

Abstract

COMMUNICATION (1 of 7)and CsSnI 3 has, to date, been less encouraging, with solar cell efficiencies of <5% for solution-processed thin film devices [10] that are likely limited by the low degree of crystalline ordering. [11] Indeed, structural ordering has been linked in traditional semiconductors to (a) carrier transport, where mobilities increase from amorphous-Si (1 cm 2 V −1 s −1 ) [12] to single crystalline Si (1400 cm 2 V −1 s −1 ), [13] (b) recombination rates, where unpassivated grain boundaries act as quenching sites for charge carriers and excited states, and (c) quantum confinement, which can make even Si an excellent NIR emitter with luminescent efficiency >60%. [14] These factors, among others, have motivated the recent interest in halide perovskite single crystal growth. [15] Thus, one of the main challenges for enhancing the properties of halide perovskites for high end optoelectronic applications is to obtain epitaxial crystalline films that can also be integrated into heteroepitaxial and quantum well structures. The epitaxial growth is a key step

Advancing Tin Halide Perovskites: Strategies toward the ASnX3 Paradigm for Efficient and Durable Optoelectronics

“…Various methods have been developed to prepare high-quality and ambient-stable Sn-based LD-PVSKs with different dimensionalities from 2D to 0D, including solvent engineering, 79 antioxidant addtion, 80,81 epitaxial growth, 82 hot-injection, [83][84][85] and ion-exchange. 86 Owing to the unique excitonic properties and enhanced stability, LD-PVSKs have been widely applied in LEDs 80,87 and PSCs.…”

Design Principles for the Atomic and Electronic Structure of Halide Perovskite Photovoltaic Materials: Insights from Computation

“…In agreement with this tolerance factor-based reasoning, DFT-computed equilibrium B-X-B bond angles correlate with the steric size of A-site cations, such that smaller A-site cations (whichl ead to smaller tolerance factors) induce highera mplitudes of octahedral rotation. [51] Strain (Figure 1c), applied through the epitaxial growth of thin films, [72,73] high pressure, [74,75] or other internal disturbances in the structure (dopants, defects, interfaces, etc. ), represents a third degree of tunability.W eh ave computed that biaxial strain is highly coupled to structurald istortion, with compressive strain enhancing the energetic driving force for octahedral rotationsand increasing their amplitude.…”

“…Strain (Figure c), applied through the epitaxial growth of thin films, high pressure, or other internal disturbances in the structure (dopants, defects, interfaces, etc. ), represents a third degree of tunability.…”

Epitaxial Metal Halide Perovskites by Inkjet‐Printing on Various Substrates

“…While epitaxy from vapors is standard for conventional inorganic semiconductors such as silicon, germanium, or III/V compounds, [ 22–26 ] it has been recently also obtained for MHPs. [ 27,28 ] Chemical vapor deposition of CH 3 NH 3 PbCl 3 on mica substrates [ 29 ] and CsPbBr 3 on SrTiO 3 [ 30 ] was successfully shown, as well as molecular beam epitaxy of CsSnBr 3 on NaCl substrates. [ 27 ] Coherent and continuous films were demonstrated in an interesting attempt called “remote epitaxy,” using polar substrates coated with graphene, to obtain epitaxial halide perovskite films with improved carrier lifetimes.…”

“…[ 27,28 ] Chemical vapor deposition of CH 3 NH 3 PbCl 3 on mica substrates [ 29 ] and CsPbBr 3 on SrTiO 3 [ 30 ] was successfully shown, as well as molecular beam epitaxy of CsSnBr 3 on NaCl substrates. [ 27 ] Coherent and continuous films were demonstrated in an interesting attempt called “remote epitaxy,” using polar substrates coated with graphene, to obtain epitaxial halide perovskite films with improved carrier lifetimes. [ 28 ] A special feature of the metal‐halide‐perovskite is that they allow processing from solutions.…”