Role of oxygen for highly conducting and transparent gallium-doped zinc oxide electrode deposited at room temperature

In this work, we found that a desirable amount of oxygen can reduce defect related scattering in enhancing carrier mobility for pulsed laser deposited zinc oxide. However, excessive oxygen can lead to formation of oxygen interstitials that can act as compensation or scattering centers. At higher oxygen pressures, structural changes that increase grain boundary scattering prove to be very important. We introduce a simple transparency index to quantify the transmission of the thin films for usage as electrodes in photovoltaic devices. An excellent resistivity of ∼3.9×10−4 Ω cm and an electron mobility of ∼19.2 cm2/V s with a transparency index of 0.84 (84% of total solar spectrum transmitted) were achieved at room temperature suggesting possible applications in plastic devices.