Characteristics of La-doped BSO(LBSO) transparent conductive oxide as a hole transport layer

BaSnO 3 (BSO) is a popular next-generation material with various applications such as solar cells and displays. However, it exhibits high electrical conductivity only in its single-crystal form. It is difficult to synthesize single crystals of a material with a perovskite structure; therefore, there has been extensive research on BSO, but this has been limited to solar cells. The improvement in electrical conductivity, carrier concentration, and mobility of spin-coated BSO through La-doping has been demonstrated by many researchers. Herein, the feasibility of spin-coated BSO as a hole transport layer (HTL) is demonstrated using doping and plating, specifically, Ag-plating is used to enhance the electrical conductivity of amorphous La-doped BSO. The proposed La-doping and Ag-plating method improved the electrical conductivity of amorphous BSO and mitigated the need of using vacuum equipment for single crystals. An OLED was fabricated using the Ag-plated LBSO as the HTL, and its EL and I–V–L characteristics were investigated. The findings of this study provide insights for further research on BSO—which is presently limited to solar cells—and demonstrate the possibility of using BSO in OLEDs. Through a 4-point probe, it was confirmed that 30 wt% of Ag-plated samples had a resistance of about 50 Ω. In addition, the I–V–L results confirmed that LBSO had a Luminance of about 190,000 cd/m 2 and a current efficiency of about 23 cd/A, and that LBSO could be used as HTL.