Comparative Study of Industry Compatible Indium-oxide based Sputtered Transparent Electrodes for Transparent Perovskite Solar Cells

The growing demand for thin-film optoelectronic and energy-harvesting devices based on sensitive photonic materials, such as organic semiconductors, perovskite, and emerging bioelectronics, underscores the critical need for low to room temperature (RT) deposition of highly transparent electrodes (TEs). This study focused on establishing a deposition mechanism to obtain highly conductive and transparent indium zinc oxide (IZO) and indium tin oxide (ITO) TEs at RT. We conducted a comparative study between amorphous indium zinc oxide (a-IZO) and polycrystalline indium tin oxide (c-ITO) after observing that superstrate-architecture transparent perovskite solar cells (T-PSCs) exhibit better performance with a-IZO rear electrodes than with c-ITO. The main reasons for the improvement in a-IZO-based devices are the low sheet resistance (22.41 sq-1), high mobility (= 32.12 cm^2 V^(-1) s^(-1)), low roughness (RMS~ 1.05 nm), and high transmittance in the infrared range (Tav ~83.5%) compared to c-ITO. Concomitant development of a controlled recipe for a MoOx interlayer (~8-10 nm) between HTL and TE allowed the development of T-PSCs without sputter damage. This study presents the first comprehensive experimental analysis of the delamination behavior of c-ITO in T-PSCs, addressing a significant gap in the literature. The occurrence of delamination in c-ITO is the primary factor contributing to its lower power conversion efficiency (PCE) of 15.84%, compared to the 18.22% achieved by a-IZO-based devices. The non-destructive nature of the TE deposition protocol suggests its viability to use on other sensitive semiconductor devices as well.