Ultrathin Wide-Bandgap a-Si:H-Based Solar Cells for Transparent Photovoltaic Applications

Abstract

Herein, the fabrication of UV-blue selective transparent solar cells based on ultrathin (<30 nm) intrinsic hydrogenated amorphous silicon films (a-Si:H) as absorber and using a fully inorganic architecture is reported, using metal-oxide thin films as carrier selective contacts and as transparent electrical contacts. These transparent ultrathin devices present a photovoltaic effect and high average visible transmittance (AVT), showing their potential as candidates for implementation as a transparent energy harvester. Potential applications range from Building-Integrated PV to agrophotovoltaics, and can also be of interest as a ubiquitous and inexpensive power source integrated in functional devices such as low-power devices, Internet of Things devices, and other sensors. Glass/FTO/ZnO/a-Si:H/MoO3/ITO device prototypes are produced. These devices present an AVT ranging from 50% to 69%, present a photovoltaic effect with a power conversion efficiency up to 0.5% calculated for an AM1.5G spectrum and have light utilization efficiency (LUE) values of 0.25%, confirming the potential of the proposed device architectures for the development of highly transparent devices with improved LUE.