Photo-electro-striction in halide perovskite semiconductors

Abstract

MAPbI3, MAPbBr3, and CsPbBr3 are excellent halide perovskite semiconductors with super long carrier diffusion length, long minority carrier lifetime, and large light absorption coefficient. Compared with the small intrinsic electrostriction, photocarriers induce a large photostriction in the surface layer. Furthermore, an electric field can efficiently separate the light excited electron–hole pairs, enhance photocarriers diffusion, and finally increase the crystal expansion, i.e., photo-electro-striction. For each crystal under 30 V/mm and in light with 450 nm wavelength and 840 mW/cm2, the photo-electro-striction is over four times of the pure electrostriction and is larger than the sum of photostriction and electrostriction. Most importantly, MAPbI3 single crystal shows a large photostriction of ∼0.35% and the photo-electro-striction of ∼0.64%. This work proves a very large photo-electro-striction as a result of the strong coupling among photocarriers, electric fields, and crystal lattices, which is important to develop semiconductor devices.

An Ultra‐Thin, Ultra‐High Capacitance Density Tantalum Capacitor for 3D Packaging

“…In contrast, the re‐passivation of Ta under constant current conditions (Figure 8a–c) is much more difficult because the anodic dissolution reaction is always going on. Despite the fact that the process from oxygen adsorption to passivation film generation has been shown to be rapid, [ 12 ] it is certain that the process still takes some time. This results in the inability to process etched foils with high SSA for constant current etching.…”

“…Our research group has been committed to solving this problem and has done a lot of research. In the previous work, the effect of etching agent type [ 12,13 ] and crystal surface orientation [ 14 ] on tantalum foil SSA has been discussed theoretically. These works have laid a good theoretical foundation for this topic.…”