Characterizing high-mobility indium zinc oxide for the front transparent conductive oxide layer in silicon heterojunction solar cells

Abstract

Silicon heterojunction solar cells have a front transparent conductive oxide (TCO) layer serving an optical and electrical role to mitigate free carrier absorption and sheet resistance. A common optimization problem is the trade-off between fill factor and short-circuit current density when adjusting the carrier concentration of the TCO material. One way to circumvent this problem is to find high-mobility TCO materials and we contribute by performing a characterization of indium zinc oxide. We found that an optimum sample has a high-mobility of about 50 cm2/Vs with a sheet resistance of about 30- $40 \Omega /\mathrm {sq}$. For the same sample, absorbance in the infrared wavelength range can be 1–3%.