Filters

2022 - 20232

More filters

2023 - 20242
Reset filters

Settings

Subject: Optoelectronic devices × WGL Institute: IFWD ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Ultrafast vibrational control of organohalide perovskite optoelectronic devices using vibrationally promoted electronic resonance
    (Basingstoke : Nature Publishing Group, 2023) Gallop, Nathaniel. P.; Maslennikov, Dmitry R.; Mondal, Navendu; Goetz, Katelyn P.; Dai, Zhenbang; Schankler, Aaron M.; Sung, Woongmo; Nihonyanagi, Satoshi; Tahara, Tahei; Bodnarchuk, Maryna I.; Kovalenko, Maksym V.; Vaynzof, Yana; Rappe, Andrew M.; Bakulin, Artem A.
    Vibrational control (VC) of photochemistry through the optical stimulation of structural dynamics is a nascent concept only recently demonstrated for model molecules in solution. Extending VC to state-of-the-art materials may lead to new applications and improved performance for optoelectronic devices. Metal halide perovskites are promising targets for VC due to their mechanical softness and the rich array of vibrational motions of both their inorganic and organic sublattices. Here, we demonstrate the ultrafast VC of FAPbBr3 perovskite solar cells via intramolecular vibrations of the formamidinium cation using spectroscopic techniques based on vibrationally promoted electronic resonance. The observed short (~300 fs) time window of VC highlights the fast dynamics of coupling between the cation and inorganic sublattice. First-principles modelling reveals that this coupling is mediated by hydrogen bonds that modulate both lead halide lattice and electronic states. Cation dynamics modulating this coupling may suppress non-radiative recombination in perovskites, leading to photovoltaics with reduced voltage losses.
  • Thumbnail Image
    Item
    Structural stability, electronic, optical, and thermoelectric properties of layered perovskite Bi2LaO4I
    (London : RSC Publishing, 2022) Joshi, Radha K.; Bhandari, Shalika R.; Ghimire, Madhav Prasad
    Layered perovskites are an interesting class of materials due to their possible applications in microelectronics and optoelectronics. Here, by means of density functional theory calculations, we investigated the structural, elastic, electronic, optical, and thermoelectric properties of the layered perovskite Bi2LaO4I within the parametrization of the standard generalized gradient approximation (GGA). The transport coefficients were evaluated by adopting Boltzmann semi-classical theory and a collision time approach. The calculated elastic constants were found to satisfy the Born criteria, indicating that Bi2LaO4I is mechanically stable. Taking into account spin-orbit coupling (SOC), the material was found to be a non-magnetic insulator, with an energy bandgap of 0.82 eV (within GGA+SOC), and 1.85 eV (within GGA+mBJ+SOC). The optical-property calculations showed this material to be optically active in the visible and ultraviolet regions, and that it may be a candidate for use in optoelectronic devices. Furthermore, this material is predicted to be a potential candidate for use in thermoelectric devices due to its large value of power factor, ranging from 2811 to 7326 μW m−1 K−2, corresponding to a temperature range of 300 K to 800 K.