相关论文: Indirect to direct bandgap transition in methylamm…
Before assessing the suitability of a semiconductor for specific applications, the first question to ask is whether it possesses a direct or indirect band gap. This distinction is fundamental, as the operation of devices such as…
We report high-pressure photoluminescence, Raman scattering, and x-ray diffraction measurements on a lead-free halide perovskite $Cs_3Sb_2Br_9$. At about 3 GPa, an electronic transition manifests itself through a broad minimum in linewidth,…
Lead halide perovskites such as methylammonium lead triiodide (MAPI) have outstanding optical and electronic properties for photovoltaic applications, yet a full understanding of how this solution processable material works so well is…
The hybrid perovskite CH3NH3PbI3 (MAPI) exhibits long minority-carrier lifetimes and diffusion lengths. We show that slow recombination originates from a spin-split indirect-gap. Large internal electric fields act on spin-orbit-coupled band…
The high performance of hybrid perovskite based devices is attributed to its excellent bulk-transport properties. However, carrier dynamics, especially at the metal-perovskite interface, and its influence on device operation are not widely…
In this paper we provide an accurate high-pressure structural and optical study of MAPbI3 hybrid perovskite. Structural data show the presence of a phase transition towards an orthorhombic structure around 0.3 GPa followed by full…
The dynamical and static Rashba effects in hybrid methylammonium (MA) lead halide perovskites have recently been theoretically predicted. However, only the static effect was experimentally confirmed so far. Here we report on the dynamical…
Mixing iodide and bromide in halide perovskite semiconductors is an effective strategy to tune their bandgap, therefore mixed-halide perovskites hold great promise for color-tunable LEDs and tandem solar cells. However, the bandgap of…
We perform a thorough structural search with the minima hopping method (MHM) to explore low-energy structures of methylammonium lead iodide. By combining the MHM with a forcefield, we efficiently screen vast portions of the configurational…
The spin-split indirect bandgap in hybrid-halide perovskites provides a momentum-space realisation of a photon-ratchet intermediate band. Excited electrons thermalise to recombination-protected Rashba pockets offset in momentum space,…
Photo- and charge-carrier induced ion migration is a major challenge when utilizing metal halide perovskite semiconductors for optoelectronic applications. For mixed iodide/bromide perovskites, the compositional instability due to light- or…
Shining light on a mixed ionic-electronic conductor induces variations in both its electronic and ionic behaviors. While optoelectronic processes in semiconductors with negligible ionic conductivities are well understood, the role of mobile…
Methylammonium lead iodide (MAPI) is a benchmark hybrid organic perovskite material, which is used for the low-cost, printed solar cells with over 20 percent power conversion efficiency. Yet, the nature of light-matter interaction in MAPI…
Halide perovskites is a new class of semiconductors with exceptional optoelectronic properties. Among many advantages offered by halide perovskites, the bandgap energy can be tuned in a much broader range than what was possible in…
Methylammonium lead triiodide perovskite (MAPbI3) semiconductor displays outstanding photovoltaic and light emitting properties. We address the unique behavior in which a bias voltage can be used to switch on and off the luminescence of a…
Through model Hamiltonian studies and first-principle electronic structure calculations, we have examined the effect of inversion symmetry breaking (ISB) field and hydrostatic pressure on the band topology of halide perovskites by taking…
Inorganic-organic lead halide perovskites, particularly methylammonium lead halide (MAPbI$_3$) perovskite, is perceived to be a promising material for optoelectronics and spintronics. However, lead toxicity and instability under air and…
Using density functional theory, the structural and electronic-structure properties of a recently discovered, zero-dimensional antimony halide perovskite are studied. It is found that the herein considered material EtPySbBr$_\mathrm{6}$…
Hot-carrier cooling (HCC) in metal halide perovskites in the high-density regime is significantly slower compared to conventional semiconductors. This effect is commonly attributed to a hot-phonon bottleneck but the influence of the lattice…
Metal halide perovskites (MHPs) are known to undergo several structural phase transitions, from lower to higher symmetry, upon heating. While structural phase transitions have been investigated by a wide range of optical, thermal and…