Absorption Spectra and Ionic Conductivity of RbxCs1-xAg4I5 Superionic Conductors Thin Films
CAO Yang1, SUN Jia-Lin1, ZHANG Guo-Sheng2, GUO Ji-Hua1, WANG Zheng-Ping2
1Key Laboratory of Atomic and Molecular Nanosciences of Education Ministry and Department of Physics, Tsinghua University, Beijing 100084
2Department of Physics, Science School, Harbin Engineering University, Harbin 150001
Absorption Spectra and Ionic Conductivity of RbxCs1-xAg4I5 Superionic Conductors Thin Films
CAO Yang1;SUN Jia-Lin1;ZHANG Guo-Sheng2;GUO Ji-Hua1;WANG Zheng-Ping2
1Key Laboratory of Atomic and Molecular Nanosciences of Education Ministry and Department of Physics, Tsinghua University, Beijing 100084
2Department of Physics, Science School, Harbin Engineering University, Harbin 150001
Abstract： A series of RbxCs1-xAg4I5 (x=0--1) thin films were grown by vacuum evaporation on NaCl crystal substrates at 350K. The absorption spectra of these films were measured at 80K in the wavelength range from 240nm to 400nm. It is shown that superionic conductor thin films of quaternary compound Rb0.5Cs0.5Ag4I5 and ternary compound RbAg4I5 can be obtained at x=0.5--0.6 and x=0.7--1, respectively. At x=0.65, the combined compound film of the mixture of 30mol\% RbAg4I5 and 70mol% Rb0.5Cs0.5Ag4I5 is presented. Then, based on the spectral positions of the A1 and A2 peaks, we determined that the Rb0.5Cs0.5Ag4I5 exciton coupling energy Rex is 0.21eV, the forbidden zone width Eg is 3.82eV and the exciton radius aex is 0.70nm. Furthermore, the ionic conductivities of superionic conductor thin films of RbAg4I5 and Rb0.5Cs0.5Ag4I5 and their mixture film are investigated, respectively, in the temperature range 303K--393K.
2005, Vol. 22 
