Carrier Transport Improvement of CHNHPbI Film by Methylamine Gas Treatment.

Recently, perovskite solar cells with high photovoltaic performance based on methylammonium lead halide have attracted great interest due to the superior physical properties of the perovskite optical absorption layer. Here, we investigate the interface carrier transport properties of CHNHPbI film by applying the reported treatment with methylamine gas, to reveal the possible mechanism of high performance perovskite-sensitized solar cell results. It is found that the crystal structure and surface morphology are effectively improved by the room-temperature repair of methylamine atmosphere.

[Raman Enhancement of a Dipolar Molecule on CVD Graphene].

The CVD graphene was chosen as the Raman enhancement substrate, graphene-enhanced Raman scattering(GERS) of dipolar molecule DREP were explored with a laser wavelength λ = 532 nm of micro-Raman spectroscopy. Upon comparison of the raman signal of DREP molecular latched to a graphene/SiO₂ substrate and to a bare SiO₂substrate, we found that the Raman signal of pure DREP molecule basically does not exist at low concentrations, until it reaches a certain concentration of 1 x 10⁻⁵ mol · L⁻¹, its Raman signal emerging and as the increasing of the concentration, Raman signal and fluorescence signal all increase. However, the raman signal of DREP molecular on the grapheme occur at the concentration of 1 x 10⁻⁷ mol · L⁻¹ and as the increasing of concentration, the raman signal increasing quickly but the fluorescence signal is not obvious.