Effect of TiO2 layer thickness of TiO2/NiO transparent photovoltaics

Abstract

AbstractThe rapid growth in the transparent electronics industry has increased the need for transparent photovoltaic cells (TPCs) and transparent self‐powered devices. To make TPCs and transparent self‐powered devices more efficient, a detailed understanding of device structure is needed. In this study, TiO2/NiO heterojunction‐based TPCs were fabricated with different TiO2 layer thicknesses, and the effect of TiO2 layer thickness on the photovoltage and photocurrent was evaluated. All the fabricated TiO2/NiO heterojunction‐based devices had a high optical transparency (>50%) in the visible–near‐infrared (vis–NIR) region. The fabricated devices were illuminated with different power sources of different wavelengths. If the TiO2 layer was too thick or too thin, the TPC performance deteriorated. By growing the optimal 100‐nm‐thick TiO2 layer, a simultaneous tunability between high optical transparency and high photovoltaic performance was achieved. A TiO2/NiO heterojunction‐based device with an optimal 100‐nm‐thick TiO2 layer had the highest optical transparency (>60%) in the vis–NIR region, with the highest photovoltage of 685.00 ± 68.06 mV and the highest photocurrent of 4.42 ± 1.35 mA under the illumination of a light source with a power density of 70 mW/cm2 at a wavelength of 365 nm. The fabricated TPCs had a high sensitivity to ultraviolet (UV) signals and demonstrated self‐powered behavior. This study clarified the role of TiO2 layer thickness optimization in improving the performance of TiO2/NiO heterojunction‐based TPCs.