Construction and photovoltaic performances of transport layer/quantum dot/transport layer sandwich nanowire arrays

The one-dimensionally ordered nanowire array with shell-core structure is an important mean to improve the photovoltaic performances of solar cells, where the core nanowire arrays can provide not only more specific surface areas, but also directional transport channels for carriers. In this work, the photovoltaic nanomaterials of transport layer/quantum dot/transport layer sandwich nanowire arrays are envisioned based on the characteristics of one-dimensionalized shell-core structure. Taking the commonly used TiO2 nanowire arrays, NiO nanofilms and lead sulfide quantum dots as electron transport material, hole transport material and absorbing layer, TiO2/PbS/NiO sandwich nanowire arrays were prepared by hydrothermal, spin-SILAR and sputtering. By the analysis of their photovoltaic performances, we found that the device has excellent broad spectrum (200-2600 nm) optical absorption and sensitive photoelectric effect with PCE reaching 6.98 %, which can fully confirm the feasibility of the transport layer/quantum dot/transport layer sandwich nanowire arrays. This will provide a new idea and basis for the development of sandwich nanowire arrays in the field of photovoltaics.