Patent ID: 8574538

Claim:
A solid material of formula (A): (Cu +1 a-u ;Ag +1 u ;Zn +2 b-v-(y/2) ;Cd +2 v ;Sn +4 c-w-(y/2) ; 1 X +4 w ; 2 X +3 y ;S −2 d-x ;Se −2 x ) (A), wherein: a, b, c, d, u, v, w, x and y and their arithmetic combinations are real numbers which represent the atomic fraction of each element with which each number is associated in formula (A), and are such that: 1.6<a<2.4; 0.6<b<1.2; 0.6<c<1.2; 3.5<d<4.5; and u, v, w, x and y, independently of one another, belong to the set of real numbers in the interval [0; 0.5], 1 X +4 is selected from the group consisting of the cations of titanium (Ti), the cations of zirconium (Zr) and the cations of lead (Pb), 2 X +3 is selected from the group consisting of the cations of gallium (Ga), the cations of indium (In) and the cations of yttrium (Y); and wherein, said solid material: is in a divided state in the form of particles having a mean equivalent diameter of from 15 nm to 400 nm; exhibits, by analysis of said solid material by X-ray diffraction, single crystal structure; and forms a stable dispersion of at least one solid material of formula (A) in any liquid, called the dispersion liquid, formed of at least one compound having a δ p value greater than 8 and a δ H value greater than 5.