4. Hole Injection Layer (HIL)
4.1 Common Materials
- CuPc (Copper phthalocyanine)
- TiOPc (Titanium oxide phthalocyanine)
- m-MTDATA (4,4',4''-Tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine)
4.1.1 CuPc (Copper phthalocyanine)
CuPc is a well-known HIL material. It has a planar molecular structure with a copper atom at the center. This structure allows it to form a stable interface with the anode and efficiently inject holes. CuPc also has good chemical stability, which is beneficial for device durability.
4.1.2 TiOPc (Titanium oxide phthalocyanine)
TiOPc is another phthalocyanine-based material for HILs. The presence of titanium in the structure can modify its electronic properties, making it suitable for hole injection. It can also have better optical and electrical properties in some cases compared to CuPc, depending on the device requirements.
4.1.3 m-MTDATA (4,4',4''-Tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine)
m-MTDATA has a complex molecular structure with multiple amino-substituted phenyl groups. This structure endows it with high hole-injection efficiency. It can effectively lower the hole-injection barrier between the anode and the HTL, promoting better device performance.