Structure and Optical Properties of
Li
x
Ag 1-
x
GaSe 2 and
Li
x
Ag 1-
x
InSe 2
ABCD PBi
Structure and Optical Properties of
Li
x
Ag 1-
x
GaSe 2 and
Li
x
Ag 1-
x
InSe 2
Autor:
Jomaa, Mohammed
;
Mishra, Vidyanshu
;
Mumbaraddi, Dundappa
;
Sikdar, Ritobroto
;
Sarkar, Diganta
;
Sun, Mengran
;
Yao, Jiyong
;
Michaelis, Vladimir K
;
Mar, Arthur
É parte de:
Inorganic chemistry, 2023-05, Vol.62 (19), p.7491-7502
Descrição:
Complete substitution of
Li
atoms for Ag atoms in AgGaSe and AgInSe was achieved, resulting in the solid solutions
Li
Ag GaSe and
Li
Ag InSe . The detailed crystal structures were determined by single-crystal
X
-ray diffraction and solid-state
Li
nuclear magnetic resonance spectroscopy, which confirm that
Li
atoms occupy unique sites and disorder only with Ag atoms. The tetragonal CuFeS -type structure (space group 4̅2 ) was retained within the entirety of the Ga-containing solid solution
Li
Ag GaSe , which is noteworthy because the end-member LiGaSe normally adopts the orthorhombic β-NaFeO -type structure (space group 2 ). These structures are closely related, being superstructures of the cubic sphalerite and hexagonal wurtzite prototypes adopted by diamond-like semiconductors. For the In-containing solid solution
Li
Ag InSe , the structure transforms from the tetragonal to orthorhombic forms as the
Li
content increases past = 0.50. The optical band gaps increase gradually with higher
Li
content, from 1.8 to 3.4 eV in Li Ag GaSe and from 1.2 to 2.5 eV in Li Ag InSe , enabling control to desired values, while the second harmonic generation responses become stronger or are similar to those of benchmark infrared nonlinear optical materials such as AgGaS . All members of these solid solutions remain congruently melting at accessible temperatures between 800 and 900 °C. Electronic structure calculations support the linear trends seen in the optical band gaps and confirm the mostly ionic character present in Li-Se bonds, in contrast to the more covalent character in Ga-Se or In-Se bonds.
Editor:
United States
Idioma:
Inglês