Bi2O3 doped indium tin oxide thin films fabricated via liquid metal printing

Abstract

Indium tin oxide (ITO) is a classical transparent conducting oxide (TCO), which is widely used in semiconductor industry. Reducing the cost of preparing ITO films and further improving its optoelectronic properties are urgent technological challenges to be solved. Here, we proposed to tackle this issue through doping elements in ITO films via liquid metals printing process. Conceptual experiments demonstrate the synthesis of Bi2O3 doped ITO at the centimeter scale using low-temperature fabrication techniques, which display the advantages of high uniformity, strong visible light transmission and low resistivity. The band gap decreases from 3.88 eV to 3.07 eV with increasing doping of Bi2O3 and demonstrates n-type semiconductor nature. The Schottky diodes based on doped ITO films show typical Ohmic contact. The best output current of doped ITO Schottky diodes can reach 1261.7 μA at 10 V, which is about 41 times the output current of the undoped ITO Schottky diodes. Additionally, the nanofilm resistance decreased linearly with increasing Bi mass fraction in ITO film. Moreover, Schottky diodes have good stability in the atmosphere within half a year and multilayer printing can enhance output current. The process as established here offers significant opportunities for future synthesis and fabrication processes in the electronics industries.