′�?, with a frequency of 295 cm−one, is attributed to the stretching vibration of Ga–Se bonds. The two-phonon absorption on the 295 cm−1 phonon corresponds into the crystal IR absorption edge, instead of the residual absorption peak. Density functional theory computations clearly show which the residual absorption of the BGSe https://jaredafghg.ltfblog.com/31709397/a-secret-weapon-for-baga4se7-crystal