Photosensitive resin composition, black pixel defining layer using the same and display device

A photosensitive resin composition, comprising:

• a binder resin, the binder resin including a polyamic acid-polyimide copolymer that includes a polyamic acid repeating unit and a polyimide repeating unit in a mole ratio of the polyamic acid repeating unit to the polyimide repeating unit of about 5:5 to about 9:1 and that has a weight average molecular weight of about 3,000 g/mol to less than 20,000 g/mol;
• a photopolymerizable monomer;
• a photopolymerization initiator including a compound represented by Chemical Formula 1;
• a black colorant;
• and
• a solvent,
• wherein, in Chemical Formula 1,
• Y1 is —NR3— or —CR4R5—,
• R3 to R5 are each independently a substituted or unsubstituted C1 to C20 alkyl group,
• R1 is a nitro group, and
• R2 is a group represented by Chemical Formula 2,
• wherein, in Chemical Formula 2,
• R6 and R7 are each independently a substituted or unsubstituted C1 to C20 alkyl group, and
• is a binding site to Chemical Formula 1.