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oe1(光电查) - 科学论文

2 条数据
?? 中文（中国） ▾

  • Impact of Organic Spacers on the Carrier Dynamics in 2D Hybrid Lead-Halide Perovskites

    摘要： We have carried out non-adiabatic molecular dynamics simulations combined with time-dependent density functional theory calculations to compare the properties of the two-dimensional (2D) (BA)2(MA)Pb2I7 and three-dimensional (3D) MAPbI3 (where MA = methylammonium and BA = butylammonium) materials. We evaluate the different impacts that the 2D-confined spacer layer of butylammonium cations and the 3D-confined methylammonium cations have on the charge carrier dynamics in the two systems. Our results indicate that while both the MA+ and BA+ cations play important roles in determining the carrier dynamics, the BA+ cations exhibit stronger non-adiabatic couplings with the 2D perovskite framework. The consequence is a faster hot-carrier decay rate in 2D (BA)2(MA)Pb2I7 than in 3D MAPbI3. Thus, tuning of the functional groups of the organic spacer cations in order to reduce the vibronic couplings between the cations and the Pb-I framework can offer the opportunity to slow down the hot-carrier relaxations and increase the carrier lifetimes in 2D lead-halide perovskites.

    关键词： carrier dynamics,2D hybrid lead-halide perovskites,time-dependent density functional theory,non-adiabatic molecular dynamics,organic spacers

    更新于2025-09-23 15:21:21

  • Highly oriented perovskites for efficient light-emitting diodes with balanced charge transport

    摘要： Ruddlesden-Popper (RP) perovskites have attracted interests due to high performance in perovskite light-emitting diodes (PeLEDs). However, the insulating organic spacers decrease carrier mobility, and increase charge accumulation and non-radiative recombination losses, which significantly undermine device performance. Herein, by blending NH3I(CH2)8NH3I (ODA) and INH3(CH2)2O(CH2)2O(CH2)2NH3I (EDBE) large organic spacers into the precursor solution, we achieve preferential orientation of perovskite crystals perpendicular to the substrate with conductive channels across the two injecting electrodes. Consequently, effective charge injection and balanced charge transport are achieved, which is beneficial to increase radiation recombination. A low turn-on voltage of 1.4 V is achieved for mixture-1.5 perovskite (ODA: EDBE=3:2, molar ratio) PeLEDs, and a maximum external quantum efficiency increases to 5.8% (EL peak ≈766 nm) at 2.0 V with a current density of 6.05 mA cm?2 compared to that of the pure ODA (2.4%) and EDBE (1.1%) devices. The findings may spur new developments in charge injection and electron-hole balance for realizing efficient PeLEDs.

    关键词： Perovskites,Ruddlesden-Popper,Organic spacers,Light-emitting diodes,Charge transport

    更新于2025-09-12 10:27:22