SPLTRAK Abstract Submission
Transparent Conductive Oxide Bi-layer as Front Contact for Multijunction Thin-film Silicon Solar Cells
Federica Saitta, Prashand Kalpoe, Paula Perez-Rodriguez, Gianluca Limodio, Rudi Santbergen, Arno H.M. Smets
TU Delft university, Delft, Netherlands

Transparent conductive oxides (TCOs) are used as front electrode of thin film silicon (TF-Si) solar cells to increase power conversion efficiency. Metal oxides doped with different materials can be deployed as TCO. The preferred TCO is usually selected using a trade-off between transparency and conductivity. This work proposes a bi-layer front contact to address the limitation of this trade-off. IOH and i-ZnO are chosen as the best candidates for such architecture due to their good opto-electrical properties. A thin layer of IOH ensures good lateral conductivity and high transparency in the visible part of the solar spectrum. An additional i-ZnO layer provides minimized parasitic absorption losses along with low transverse resistivity. The best opto-electrical properties are achieved when deposition temperature and power density are set at 25 °C and 1.5 W/cm2, 200 °C and 2 W/cm2 for IOH and i-ZnO respectively.