Improved Electrical and Optical Properties of IGZO Transparent Conductive Oxide Due to Microwave Treatment: Application to Silicon Solar Cells

Abstract

The electrical and optical properties of IGZO-based transparent conductive oxide (TCO), fabricated by reactive-sputtering, are optimized using post microwave treatment (MWT), not rapid temperature annealing (RTA), for silicon solar cell. Compared to the sheet resistance and transmittance of IGZO-based TCO after RTA and MWT, we observed a transmittance of over 75 % in the visible and near ultraviolet range of 370-1,200 nm in common, while the lower sheet resistance of 15 $\Omega $ / was obtained, which was 3.5 times lower than that of the RTA sample, which resulted in higher current density in IGZO-based TCO after MWT. On the basis of trap density analysis, it is confirmed that the oxygen vacancy within IGZO-based TCO increased as process and power in MWT, which is the reason for the increase in conductivity. Furthermore, short circuit current density ( $\text{J}_{\mathrm {sc}}$ ) was compared to confirm the applicability in the solar cell, which is one of the fields that IGZO mainly uses as a TCO. $\text{J}_{\mathrm {sc}}$ of the IGZO based solar cell annealed in MWT at 400W for 60 s was 19.8 mA/cm2.

Keywords

• Microwave treatment
• TCO
• IGZO
• solar cell