First-principles Studies of Second-Order Nonlinear Optical Properties of Organic-Inorganic Hybrid Halide Perovskites

Abstract

Organic-inorganic hybrid halide perovskites have ignited tremendous interests for photovoltaic applications. However, their nonlinear optical response has not been studied although many of these structures lack the centrosymmetry and exhibit ferroelectricity. In this work, we employ our developed large-scale parallel, first-principles simulation tool (ArchNLO) to explore secondorder nonlinear optical properties of a typical family of organic-inorganic hybrid halide perovskites, CH3NH3MX3 (M= Ge, Sn, Pb; X=Cl, Br, I). We find that these hybrid perovskites exhibit second harmonic generation and linear electro-optic effect. The nonlinear optical effects are strongly influenced by the types and positions of cations/anions and corresponding band gaps.Particularly, the distorted cubic phase, which is essentially triclinic, of CH3NH3SnI3 shows significant second harmonic generation and electro-optic effect, which are comparable with those widely used materials, such as GaAs. These second-order optical properties of organic-inorganic hybrid halide perovskites and their low-temperature, solution-based fabrication pave the way for achieving and implementing nonlinear optical devices with low cost.Nonlinear optical (NLO) materials play a critical role in modern electronics and photonics by providing means to alter the phase, frequency or amplitude of input electromagnetic waves. Such alternation can be realized through a variety of nonlinear processes, such as the linear electrooptic (LEO) effect, second/third/fourth/high harmonic generation (SHG/THG/FHG/HHG), and the Kerr effect, etc.[1] The group of traditional NLO materials are ternary inorganic oxides and their derivatives., e.g., lithium niobate and lithium tantalate. They have achieved widespread success due to their reliable performance, low optical loss, and good stability. However, the synthesis of these insoluble oxides requires the high temperature treatment, which hinders broader applications for flexible substrates and the integration into chip-scale nanophotonic devices. In contrast to their inorganic counterparts, organic NLO materials based on chromophores have been considered as a promising alternative due to their solution processability, faster response, and stronger NLO activities. Unfortunately, the low intrinsic stability and high optical loss severely limit their applications [2].Nowadays, organic-inorganic hybrid halide perovskites (OHPs) have attracted tremendous interest in emerging photovoltaic (PV) technologies. Extensive theoretical exploration has been applied to studying their linear optical responses related to PV, including self-consistent density functional theory (DFT) approaches as well as quasiparticle methods [3][4][5]. On the other hand, due to the asymmetry of the organic unit, ferroelectricity can be realized in this family of materials naturally or by artificially tuning [6][7][8][9]. This broken inversion symmetry also ensures NLO properties [10], especially second harmonic generation (SHG) and linear electro-optic (LEO) effects [1...

Tunable Second Harmonic Generation in Twisted Bilayer Graphene

“…31,32 Moreover, the resonant and dispersive behavior of tBLG in the visible range due to the semimetal and anticrossed band structure point toward the failure of Kleinman symmetry in describing the second-order susceptibility. 33 Thus, the contribution from the chiral tensor component c xyz cannot be neglected here, and this prediction agrees with both density functional theory (DFT) simulations 34 and our SHG polarization measurements as shown below.…”

Suppression of second-harmonic generation from linear bands in the topological multifold semimetal RhSi

“…1). The best agreement with the data is obtained after correcting the bare separation between bands by incorporating many-body effects [37][38][39][40][41], suggesting that capturing other nonlinear responses in chiral topological semimetals may require these corrections as well.…”

Basic formulation and first-principles implementation of nonlinear magneto-optical effects

“…The first term in Eq. ( 16) survives under T symmetry and is included in the conventional SHG expression [22,24,[28][29][30][31][32][33][34][35][36]. In addition, the first term is purely real in the static limit.…”

“…[22] with low-frequency divergent problem shown in Eq. ( 14), the 'T -SMP' expression in which the lowfrequency divergent terms are simplified by T symmetry and have been implemented in many calculation packages [30][31][32][33][34][35][36], and the full-frequency convergent expression 'CVG' proposed in this paper as demonstrated in Eq. ( 15).…”

“…However, the divergence could be problematic for magnetic materials. The T -symmetry simplified (T -smp) expression in which T symmetry is only applied to the divergent terms have been implemented in many computational codes [30][31][32][33][34][35][36] and reasonable agreement between theoretical predictions and experiments has been reached for non-magnetic materials [37]. While T -smp expressions can still be used to estimate the SHG susceptibility in magnetic materials [38], the divergent terms that are unique to magnetic materials are missing.…”