Sputtering of Molybdenum as a Promising Back Electrode Candidate for Superstrate Structured Sb₂S₃ Solar Cells

Abstract

Sb2S3 is rapidly developed as light absorber material for solar cells due to its excellent photoelectric properties. However, the use of the organic hole transport layer of Spiro‐OMeTAD and gold (Au) in Sb2S3 solar cells imposes serious problems in stability and cost. In this work, low‐cost molybdenum (Mo) prepared by magnetron sputtering is demonstrated to serve as a back electrode in superstrate structured Sb2S3 solar cells for the first time. And a multifunctional layer of Se is inserted between Sb2S3/Mo interface by evaporation, which plays vital roles as: i) soft loading of high‐energy Mo particles with the help of cottonlike‐Se layer; ii) formation of surficial Sb2Se3 on Sb2S3 layer, and then reducing hole transportation barrier. To further alleviate the roll‐over effect, a pre‐selenide Mo target and consequentially form a MoSe2 is skillfully sputtered, which is expected to manipulate the band alignment and render an enhanced holes extraction. Impressively, the device with an optimized Mo electrode achieves an efficiency of 5.1%, which is one of the highest values among non‐noble metal electrode based Sb2S3 solar cells. This work sheds light on the potential development of low‐cost metal electrodes for superstrate Sb2S3 devices by carefully designing the back contact interface.

Improving the efficiency of a CIGS solar cell to above 31% with Sb2S3 as a new BSF: a numerical simulation approach by SCAPS-1D

“…Although some researchers also used Au and Mo as a back contact layer with Sb 2 S 3 layer. 34–38 This innovative solar cell design consists of a p-type CIGS absorber layer with a thickness of 1.0 μm, a p + type Sb 2 S 3 BSF layer of 0.2 μm on the back Ni layer, an FTO window layer measuring 0.05 μm and an n-type SnS 2 buffer layer of 0.05 μm. Aluminum (Al) is the selected material for the front grid contact because of its high work function of 4.06 eV, allowing it to efficiently extract and transport the generated charge carriers in a solar cell.…”