Samsung patents lead-free sensor layer for cameras

1. A perovskite photodiode, comprising: a first electrode and a second electrode, a perovskite photoelectric conversion layer between the first electrode and the second electrode, the perovskite photoelectric conversion layer including a Pb-free perovskite, and an auxiliary layer between the first electrode and the perovskite photoelectric conversion layer, the auxiliary layer including a compound represented by Chemical Formula 1: wherein, in Chemical Formula 1, X 1 and X 2 are different from each other and each is CR a R b, SiR c R d, or NR c, R 2 to R 5 are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C3 to C20 heterocyclic group, a halogen, a cyano group, —NR f R g, or any combination thereof, R a to R g are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C3 to C20 heterocyclic group, a halogen, a cyano group, or any combination thereof, R a and R b are each independently present or are combined with each other to form a first ring, R c and R d are each independently present or are combined with each other to form a second-ring, and ring, R f and R g are each independently present or are combined with each other to form a third ring, and R 1 and R 6 in Chemical Formula 1 are each —NR f R g, wherein R f and R g are each a substituted or unsubstituted C6 to C20 aryl group, and R f and R g are bonded to each other through a single bond, a substituted or unsubstituted C1 to C5 alkylene group, a substituted or unsubstituted C2 to C5 alkenylene group, a substituted or unsubstituted C6 to C20 arylene group, O, S, Se, Te, CR h R i, SiR j R k, or GeR l R m to form a separate ring, wherein R h to R m are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C3 to C20 heterocyclic group, a halogen, a cyano group, or any combination thereof.