ABSTRACT
The effect of localized plasmon on the photoemission and absorption in hybrid molybdenum disulfide-Gallium nitride (MoS2-GaN) heterostructure has been studied. Localized plasmon induced by platinum nanoparticles was resonantly coupled to the bandedge states of GaN to enhance the UV emission from the hybrid semiconductor system. The presence of the platinum nanoparticles also increases the effective absorption and the transient gain of the excitonic absorption in MoS2. Localized plasmons were also resonantly coupled to the defect states of GaN and the exciton states using gold nanoparticles. The transfer of hot carriers from Au plasmons to the conduction band of MoS2 and the trapping of excited carriers in MoS2 within GaN defects results in transient plasmon-induced transparency at ~1.28 ps. Selective optical excitation of the specific resonances in the presence of the localized plasmons can be used to tune the absorption or emission properties of this layered 2D-3D semiconductor material system.
ABSTRACT
Organic-inorganic hybrid perovskites have attracted intensive attention due to their exceptional optoelectronic properties. With a massive leap of efficiency from 3.8% to 25.2% in a decade, perovskite solar cells (PSCs) have been considered the most promising next-generation photovoltaic technology. Recently, the methylamine (MA)-gas-mediated approach has been widely studied for preparing precursor solutions to deposit large scale perovskite thin films for PSCs. In this article, high-quality MAPbI3 films were spin-coated using a MA-gas-mediated perovskite precursor. The deposited MAPbI3 films showed larger crystal grains, lower surface roughness, and a preferred (110) crystal orientation compared to the films deposited by the Lewis adduct method. Planar PSC devices fabricated using the MA-gas-mediated precursor showed a high efficiency of 19.28% and a higher average efficiency than the devices fabricated by the Lewis adduct method.
