Enhancement of band gap and birefringence induced via π-conjugated chromophore with “tail effect”

Abstract

Birefringent materials, the crucial component in modulating the polarization of light, exert of great significance in optical communication and the laser industry. However, it is difficult to dig out excellent...

Mg(H2O)6[(IO2(OH))2(IO3)]2: a new iodate with a very large band gap and optical anisotropy

“…42 In addition, the coordinated aqua ligands may also be expected to contribute to improving the birefringence. 43…”

Performance of optical materials with the derivative of planar π-conjugated groups: Recent advances and future prospects

“…The AHCO 3 (A = Na, K, Rb, Cs) series were screened out based on a thorough investigation in the ICSD, version 4.6.0 and only NaHCO 3 is discussed here. [85][86][87][88][89] In its structure (Fig. 19), planar [CO 2 (OH)] triangles connect with each other through O-H⋯O hydrogen bonds to construct an infinite [HCO 3 ] chain along the c axis with Na cations filling between the chains.…”

Crystal Growth of K2HCO3F·H2O with a Very Short Cutoff Edge and Large Birefringence

“…Although the crystal structure of K 2 HCO 3 F•H 2 O has been reported previously, 40 we redetermined the structure after growing crystals of the title compound to better understand the structure−property relationships. K 2 HCO 3 F•H 2 O crystallizes in the centrosym- 33 If H + is introduced into the CO 3 2− group, the corresponding oxygen atoms' dangling bonds are eliminated and the UV cutoff edges are subsequently extended. 22,55 The short cutoff edge observed from the title compound should be attributed to the cooperation of HCO 3 − and F − .…”

“…26−32 Another recently reported interesting method includes introducing H atoms into the πconjugated groups. 33 For example, the HCO 3 − group with the introduced H atom can further interact with other atoms, which effectively eliminates dangling bonds in the structure and subsequently keeps the compound's large birefringence and band gap. 33 Another critical reason of the short cutoff edge for KBBF is the existence of the highly electronegative F atoms in the structure.…”

“…33 For example, the HCO 3 − group with the introduced H atom can further interact with other atoms, which effectively eliminates dangling bonds in the structure and subsequently keeps the compound's large birefringence and band gap. 33 Another critical reason of the short cutoff edge for KBBF is the existence of the highly electronegative F atoms in the structure. Through effective approaches, a number of new compounds applicable in the DUV regions have been successfully suggested.…”