Precursor solution for copper-zinc-tin-sulfur thin film solar cell, preparation method therefor, and use thereof

A precursor solution for CZTS thin film solar cell, wherein

• the precursor solution is prepared by using a DMSO or a DMF as a solvent, and a precursor compound as a solute;
• the precursor compound is composed of metal complexes, a metal salt and a thiourea,
• wherein the metal complexes are a copper complex formed by a copper salt, and a thiourea or thiourea derivative, and
• a tin complex formed by a tin salt, and a DMF or DMSO, and
• the metal salt is a divalent zinc salt;
• and
• the precursor compound is dissolved in the solvent of the DMSO or DMF to obtain a stable, clear and transparent precursor solution,
• the copper complex is a complex formed by a copper salt, and a thiourea or derivative, including a complex of Cu(Tu)3X formed by a copper halide and a thiourea, wherein X is a halogen element including F, Cl, Br, and I,
• the formed copper complex includes Cu(Tu)3Cl, [Cu2(Tu)6]Cl2.2H2O, and Cu(Tu)3Br,
• the formed copper complex further includes a complex of Cu(DMTu)3Br, Cu(TMTu)3Cl, and [Cu(ETu)2Br]2 formed by a copper halide and a thiourea derivative, wherein the DMTu is N, N-dimethylthiourea, the TMTU is tetramethylthiourea, and the Etu is ethylene thiourea;
• and
• the formed copper complex further includes a complex of Cu4(Tu)10(NO3).Tu.3H2O formed by a copper nitrate salt and a thiourea;
• the tin complex is selected from one or more of Sn(X)yCl4, Sn(X)yF4, Sn(X)yBr4, Sn(X)yI4, and Sn(X)y(CH3COO)4, X is selected from one of DMSO, DMF, ethanol, and N-methylpyrrolidone, and y is a natural number greater than zero;
• and
• a specific method for preparing the precursor solution is:
• taking DMSO or DMF as the solvent, dissolving the copper complex and the tin complex, the zinc salt and the thiourea directly into the solvent, to obtain the clear and transparent precursor solution.