Heterojunction solar cell with 6% efficiency based on an n-type aluminum–gallium–oxide thin film and p-type sodium-doped Cu₂O sheet

Abstract

In this paper, we describe efforts to enhance the efficiency of Cu 2 O-based heterojunction solar cells fabricated with an aluminum-gallium-oxide (Al-Ga-O) thin film as the n-type layer and a p-type sodium (Na)-doped Cu 2 O (Cu 2 O:Na) sheet prepared by thermally oxidizing copper sheets. The optimal Al content [X; Al/(Ga + Al) atomic ratio] of an Al X -Ga 1%X -O thin-film n-type layer was found to be approximately 2.5 at. %. The optimized resistivity was approximately 15 Ω cm for n-type Al X -Ga 1%X -O/p-type Cu 2 O:Na heterojunction solar cells. A MgF 2 /AZO/Al 0.025 -Ga 0.975 -O/ Cu 2 O:Na heterojunction solar cell with 6.1% efficiency was fabricated using a 60-nm-thick n-type oxide thin-film layer and a 0.2-mm-thick Cu 2 O:Na sheet with the optimized resistivity.

Current Status and Future Prospects of Copper Oxide Heterojunction Solar Cells

“…The Cu 2 O heterojunction solar cell with the highest η (as of 2015) was reported by Minami et al [34]. This cell was fabricated on a Cu 2 O substrate formed by thermal oxidation of high purity Cu sheets.…”

Heteroepitaxial Cu2O thin film solar cell on metallic substrates

“…In order to fabricate high-performance Cu 2 O solar cells, it is vital to have excellent transport properties (carrier density and mobility, and minority carrier life time) inside Cu 2 O layer and at the junction interface. However, most Cu 2 O films have been prepared on un-textured or polycrystalline substrates by thermal oxidation, electro-deposition, and sputtering methods147891011121314151617181920. As a result, the films have a polycrystalline nature and rough surface morphologies, resulting in very defective films as well as poor interfaces at junctions and/or metal contacts comprising the cells.…”

Nanoparticle-based screen printing of copper zinc tin sulfide thin film as photocathode for quantum dot sensitized solar cell

“…[5,7] To date, hydrazine-processed CZTS(Se) devices hold the power conversion efficiency record at 12.6%, whose quantum efficiency is ~90% in the visible region. [8] The efficiency is still lower than solar cells based on CIGSSe (20.3% [9]) and CdTe (21.5%, First Solar), but walks over those oxide thin film solar cells, such as Cu 2 O (6.1% [10]). However, the toxicity of hydrazine becomes the shortcoming of this method.…”