Solid material in the divided state, process for the production of such a material, and use of such a material in a photovoltaic cell

A solid material of formula (A):

• (Cu+1a-u;Ag+1u;Zn+2b-v-(y/2);Cd+2v;Sn+4c-w-(y/2);1X+4w;2X+3y;S−2d-x;Se−2x) (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],
• 1X+4 is selected from the group consisting of the cations of titanium (Ti), the cations of zirconium (Zr) and the cations of lead (Pb),
• 2X+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 δp value greater than 8 and a δH value greater than 5.