Influence of Ga-doped transparent conducting ZnO thin film for efficiency enhancement in organic light-emitting diode applications

In this paper, transparent conducting n-type ZnO:Ga and commercially available SnO2:F (U-type Asahi) thin films have been used as a front electrode (Anode) in organic light-emitting diode (OLED)-based display devices. RF magnetron sputtered ZnO:Ga thin films with an electrical resistivity of 9.6x10-5 Omega -cm, low sheet resistance less than 5.6 Omega/square and optical transparency greater than 90% have been reported at room temperature (RT) using the glass substrate. The OLED device structure consists of transparent conducting oxide (TCO) (170 nm)/HAT-CN (15 nm)/TAPC (30 nm)/CBP:Ir(ppy)3(30nm; 8wt%)/BPhen(50 nm)/LiF (1 nm)/Al (120 nm). Normalized intensity of both types TCO (ZnO:Ga and SnO2:F)-based OLED shows a similar kind of result. The results suggest that Ga-doped ZnO thin films are the substitutional anode materials of commercially established SnO2:F (fluorine-doped tin oxide), ITO (tin-doped indium oxide) for the OLED application, and also in other optoelectronic devices. The important figures of merit such as external quantum efficiency, current and power efficiency of ZnO:Ga (GZO)-based OLED are demonstrated and compared with SnO2:F (FTO)-based OLED. These results suggest that Ga-doped ZnO thin films can be a promising candidate as the anode layer in OLEDs as a substitution to ITO and SnO2:F film.

Automated summary

The study demonstrates that Ga-doped ZnO thin films can serve as a promising alternative anode material in OLEDs, replacing ITO and SnO2:F films. Experimental results show that ZnO:Ga films exhibit excellent performance in terms of transparency and electrical properties, suitable for OLEDs and other optoelectronic devices.