Innovative fs Laser Processing Technique Combining Metal Nanoparticle Deposition for High-Performance Perovskite Optoelectronic Devices

In recent years, micronano-structure-functionalized perovskite optoelectronics, which can improve their photoluminescence and photoelectric properties, have been booming. The traditional fabrication processes of micronano-patterned perovskites, such as nanoimprint and optical lithography have complex processes and high environmental requirements. In this article, a method based on a laser-induced periodic surface structure and controlled deposition of metal nanoparticles is first proposed to enhance the light absorption of optoelectronic devices. This method specifically includes wet etching-assisted femtosecond laser writing and deposition of Au nanoparticles by a galvanic displacement reaction. The finite-difference time-domain simulation results show that compared with the silicon substrate without Au nanoparticles, the light absorption rate of the silicon substrate with Au nanoparticles at 300 and 600 nm increased by about 6 and 5.5%, respectively, which is also proved by ultrafast transient absorption spectroscopy. The results of scanning electron microscopy images and energy-dispersive spectrometry mappings show that the deposition density and uniformity of Au nanoparticles are the best when the deposition time is 2.5 min. The photocurrent of the perovskite photodetector prepared in this way shows an enhanced photocurrent, which is about three times that of the device without any treatment. This method has potential applications in photodetectors, solar cells, and so on.