Investigation of the charge injection from Organometal halide perovskite to a hole transport layer using a heterodyne transient grating spectroscopic technique

Ultrafast Optical Control of Exciton Diffusion in WSe2/Graphene Heterostructures Revealed by Heterodyne Transient Grating Spectroscopy

“…Ultrafast techniques such as time- and angle-resolved photoelectron spectroscopy have been employed to investigate the charge transfer and carrier dynamics in these HSs, as well as transient absorption (TA) spectroscopy and microscopy, , terahertz-, − Raman- , and photoluminescence-spectroscopy. , Our study adds another piece to the puzzle by using TA and heterodyned transient grating (TG) spectroscopy to investigate Gr’s influence on the spatiotemporal charge dynamics of the HS. TG spectroscopy is a powerful, all-optical tool for studying the ambipolar diffusion and lifetime of excited charge carriers in various materials on time scales ranging from pico- to microseconds. − Detailed sample information is available in the Supporting Information (SI). We found that photoexcitation of the WSe 2 /Gr HS causes transient photodoping effect in Gr, altering exciton binding energies in WSe 2 due to transient dielectric screening, which improves exciton diffusion within the WSe 2 layer by minimizing charge trap and defect impact.…”