Transparent conductive oxides represent a critical materials platform for modern optoelectronic applications, particularly in photovoltaic devices where the transparent electrode substantially influences device performance parameters. This investigation examined the systematic effects of sputtering working pressure on the structural, optical, and electrical properties of InZnO (IZO) and Mg-doped IZO (IZMO) thin films deposited via radiofrequency magnetron sputtering. Results demonstrate that reducing working pressure enhances carrier mobility from 8.48 to 31.8 cm 2 /V·s and increases carrier concentration while widening optical bandgap. However, the dominant mechanism for bandgap widening differs between the two systems: for IZO, it is primarily attributed to reduced defect states from improved short-range order, while for IZMO, both the Burstein-Moss effect and defect reduction contribute. The Mg-doped variant exhibited superior photovoltaic performance, achieving 18.97% efficiency in Cu(In,Ga)Se 2 solar cells compared to 17.03% for the undoped composition. These findings establish material-specific optimal deposition conditions—with IZMO achieving peak performance at a higher working pressure (1.50 Pa) than IZO (0.25 Pa)—and demonstrate that compositional engineering effectively balances competing optical and electrical properties for enhanced device performance. • Systematic investigation of sputtering pressure effects on InZnO and InZnMgO thin films. • Lower deposition pressure enhances conductivity and widens the optical bandgap. • Mg-doping effectively breaks the inherent trade-off in transparent conductor performance. • InZnMgO based CIGSe solar cells achieved 18.97% PCE, outperforming InZnO.
Egyna et al. (Sun,) studied this question.