Tris(4-carbazoyl-9-ylphenyl)amine

Having three carbazole units as the pendants and triarylamine at the core, tris(4-carbazoyl-9-ylphenyl)amine (TCTA) is electron-rich. With low electron mobility, TCTA has also been used as exciton/electron blocking layer materials because of its high lying LUMO energy level (LUMO = 2.4 eV).

TCTA is widely used as a hole-transport and hole-injection material in light-emitting diodes and perovskite solar cells.

TCTA is a very popular phosphorescent host material due to its large band gap (Eg = 3.4 eV) for green, red and white phosphorescent organic light-emitting diodes (PhOLEDs).

Examples of OLED device performance:

1. ITO/NPD/TCTA/BCPO:Ir(piq)₃ (7-8%)/BCP/Alq₃/LiF/Al
Color: red
Max. Luminance: 24529 Cd/m²
Max. EQE: 17 %
Turn-On Voltage: 2.7 V

2. ITO/NPD/TCTA/BCPO:Ir(ppy)3 (7-8%)/BCP/Alq₃/LiF/Al
Color: green
Max. Luminance: 207839 Cd/m²
Max. EQE: 21.6 %
Turn-On Voltage: 2.1 V

3. ITO/PEDOT:PSS/NPD/TCTA/m-CBTZ:FIrpic (10 wt%)/DPPS/TAZ/LiF/Al
Color: blue
Max. Luminance: 29500 Cd/m²
Max. EQE: 8.8 %
Turn-On Voltage: 3.5 V

4. ITO/PEDOT:PSS/NPD/TCTA/m-CBTZ:Ir(Bt)₂(acac) (10%)/TPBI/LiF/Al
Color: yellow
Max. Luminance: 106000 Cd/m²
Max. EQE: 17.5 %
Turn-On Voltage: 3 V

TCTA is widely used as a hole transport material in OLED and organic photovoltaic (OPV) devices. It possesses excellent hole injection and transport properties, helping to efficiently transport positive charges (holes) from the anode to the emitting layer, enabling improved device efficiency and stability.