Yb-doped zinc tin oxide thin film and its application to Cu(InGa)Se2 solar cells

Youngsang Park (1) , Gerald Ferblantier (2) , Abdelilah Slaoui (2) , Aziz Dinia (3) , Hyeonwook Park (4) , Salh Alhammadi (4) , Woo Kyoung Kim (4)

1 YeungNam University
2 ICube - Laboratoire des sciences de l'ingénieur, de l'informatique et de l'imagerie
3 IPCMS - Institut de Physique et Chimie des Matériaux de Strasbourg
4 Yeungnam University [South Korea]

The use of rare earth elements with semiconductor materials has attracted immense interest due to their unique properties. In this study, we investigated the characteristics of an ytterbium (Yb)-doped zinc tin oxide (Yb:ZTO) thin film and its application as a potential down-converter of Cu(InGa)Se 2 (CIGS) thin-film solar cells. Yb:ZTO thin films were deposited by reactive sputtering of Zn and Sn metal with oxygen flow. A few pieces of Yb were embedded in a Zn metal target; thus Yb elements were supplied during Zn sputtering. The relative composition of Zn and Sn was controlled by changing the sputtering power (10-70 W) of Sn, in relation to the fixed sputtering power for Zn (70 W). In addition, the substrate temperature was varied from room temperature to 400°C. It was confirmed that a smaller amount of Sn with lower sputtering power led to more incorporation of Yb into ZTO. X-ray photoelectron spectroscopy analysis confirmed the incorporation of Yb into ZTO, and photoluminescence measurement demonstrated Yb emission. Grazing incidence X-ray diffraction indicated the shift of ZTO emission peaks induced by the difference in the composition of Zn and Sn. Finally, CIGS solar cells with an Yb:ZTO layer were fabricated. The results suggested that cells with the highest Yb photoluminescence emission showed the highest short-circuit current density and cell efficiency.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Youngsang Park, Gerald Ferblantier, Abdelilah Slaoui, Aziz Dinia, Hyeonwook Park, et al.. Yb-doped zinc tin oxide thin film and its application to Cu(InGa)Se2 solar cells. Journal of Alloys and Compounds, 2020, 815, pp.152360. ⟨10.1016/j.jallcom.2019.152360⟩. ⟨hal-02550925⟩