Highly efficient unbridged D-A+(D) chromophores based on the quinolizinium cation for nonlinear optical (NLO) applications

Recent Advances in the Asymmetric Growth of Organic Polar Crystals: A Review

“…The urgent demand for nonlinear optical materials has led researchers to gradually extend their attention from inorganic to organic materials. Nowadays, organic polar crystals have been continuously explored and are expected to surpass inorganic polar crystals as the new generation of functional materials owing to their advantages of ultrafast nonlinear optical response, low dielectric constant, and strong molecular designability. − The formation of crystals with the polar axis is one of the most interesting aspects of solid-state chemistry, which is a property exhibited by many common organic and inorganic materials . Unfortunately, these highly polar, noncentrosymmetric organic polar materials tend to rapidly grow along the polar axis; therefore, whenever this process is not effectively controlled, it can easily lead to the formation of imperfect crystals, with rough surfaces, twin boundaries, and narrow-line defects in the bulk .…”