Manipulation of hot carrier cooling dynamics in two-dimensional Dion–Jacobson hybrid perovskites via Rashba band splitting

Abstract

Hot-carrier cooling processes of perovskite materials are typically described by a single parabolic band model that includes the effects of carrier-phonon scattering, hot phonon bottleneck, and Auger heating. However, little is known (if anything) about the cooling processes in which the spin-degenerate parabolic band splits into two spin-polarized bands, i.e., the Rashba band splitting effect. Here, we investigated the hot-carrier cooling processes for two slightly different compositions of two-dimensional Dion–Jacobson hybrid perovskites, namely, (3AMP)PbI4 and (4AMP)PbI4 (3AMP = 3-(aminomethyl)piperidinium; 4AMP = 4-(aminomethyl)piperidinium), using a combination of ultrafast transient absorption spectroscopy and first-principles calculations. In (4AMP)PbI4, upon Rashba band splitting, the spin-dependent scattering of hot electrons is responsible for accelerating hot-carrier cooling at longer delays. Importantly, the hot-carrier cooling of (4AMP)PbI4 can be extended by manipulating the spin state of the hot carriers. Our findings suggest a new approach for prolonging hot-carrier cooling in hybrid perovskites, which is conducive to further improving the performance of hot-carrier-based optoelectronic and spintronic devices.

Carrier dynamics in two-dimensional perovskites: Dion–Jacobson vs. Ruddlesden–Popper thin films

“…Generally, the fast component is related to exciton formation, and the slow component is determined by carrier recombination. 43,44 The kinetic curves are fitted by using a triple-exponential function, Δ A ( t ) = a 1 exp(− t / τ 1 ) + a 2 exp(− t / τ 2 ) − c 1 exp(− t / τ et ), where a 1 , a 2 , and c 1 are amplitudes, τ 1 and τ 2 are the decay time constants, and τ et is formation time constant. 45,46 The insets of Fig.…”

Spin–Orbit Coupling in 2D Semiconductors: A Theoretical Perspective

“…Furthermore, Rashba states should locate in the valence band maximum (VBM) or conduction band minimum (CBM) for practical applications. In this section, we summarize a series of 2D Rashba semiconductors theoretically, including AB binary buckled monolayers, − Janus monolayers (especially for MXY Janus monolayers), − 2D perovskites, ,− and so on. As for 2D Dresselhaus semiconductors, although we have summarized the linear Dresselhaus Hamiltonian of 2D electron gas systems theoretically, there are no 2D semiconductors that demonstrate the pure Dresselhaus effect theoretically and experimentally, where “the pure Dresselhaus effect” means the absence of the Rashba effect.…”

“…For example, the Rashba effect for 2D (ATHP) 2 PbBr 4 (where ATHP indicates 4-aminotetrahydropyran) perovskite (α = 0.65 eV·Å in the CBM and α = 0.16 eV·Å in the VBM) is related to the polarization, which originates from the dipole moment of organic cations . The Rashba effect for 2D (4AMP)­PbI 4 (where 4AMP indicates 4-(aminomethyl)­piperidinium) perovskite (α = 1.46 eV·Å in the VBM) with Pc space group is attributed to the inversion symmetry by polar octahedral distortions . (C 6 H 5 C 2 H 4 NH 3 ) 2 PbI 4 has α equaling 1.6 ± 0.1 eV·Å, which is on account of the Pb atom displacement from the octahedral center …”

“…In the last subsection, we will review ferroelectric Rashba semiconductors, where the external electric field can switch between two ferroelectric states and reverse the spin texture of the Rashba bands. − This nonvolatile approach to control the spin degrees of freedom plays an important role in spintronics, especially in spin orbitronics . Several binary buckled hexagonal monolayers (BiSb, SiGe, SiSn, AlSb, GaP, GaAs, InP, InAs, and InSb), , binary buckled square PbX (X = S, Se, Te) monolayers, , and 2D Rashba perovskites (2D (ATHP) 2 PbBr 4 , (4AMP)­PbI 4 ) ,, possess ferroelectric polarization. In the case of 2D Rashba perovskites, 2D (ATHP) 2 PbBr 4 and (4AMP)­PbI 4 possess robust ferroelectricity. ,, Regarding MXY Janus monolayers, ferroelectric distorted 1T-phase TMDs MX 2 (M= Mo, W; X= S, Se, Te) monolayers have been predicted to have the Rashba effect. ,, Encouragingly, d1T-MoTe 2 (distorted 1T-phase MoTe 2 ) monolayer has been realized experimentally .…”

“…Several binary buckled hexagonal monolayers (BiSb, SiGe, SiSn, AlSb, GaP, GaAs, InP, InAs, and InSb), , binary buckled square PbX (X = S, Se, Te) monolayers, , and 2D Rashba perovskites (2D (ATHP) 2 PbBr 4 , (4AMP)­PbI 4 ) ,, possess ferroelectric polarization. In the case of 2D Rashba perovskites, 2D (ATHP) 2 PbBr 4 and (4AMP)­PbI 4 possess robust ferroelectricity. ,, Regarding MXY Janus monolayers, ferroelectric distorted 1T-phase TMDs MX 2 (M= Mo, W; X= S, Se, Te) monolayers have been predicted to have the Rashba effect. ,, Encouragingly, d1T-MoTe 2 (distorted 1T-phase MoTe 2 ) monolayer has been realized experimentally . In addition, d1T-WS 2 monolayer has the largest Rashba energy among six distorted 1T-phase MX 2 structures .…”