Theoretical Insight into High‐Efficiency Triple‐Junction Tandem Solar Cells via the Band Engineering of Antimony Chalcogenides

Abstract

Antimony chalcogenides have become a family of promising photoelectric materials for high‐efficiency solar cells. To date, single‐junction solar cells based on individual antimony selenide or sulfide are dominant and show limited photoelectric conversion efficiency. Therefore, great gaps remain for the multiple junction solar cells. Herein, triple‐junction antimony chalcogenides‐based solar cells are designed and optimized with a theoretical efficiency of 32.98% through band engineering strategies with Sb2S3/Sb2(S0.7Se0.3)3/Sb2Se3 stacking. The optimum Se content of the mid‐cell should be maintained low, i.e., 30% for achieving a low defect density in an absorber layer. Therefore, Sb2(S0.7Se0.3)3‐based mid solar cells have contributed to elevate the external quantum efficiency in triple‐junction devices by the full utilization of the solar spectrum. In a single‐junction solar cell, the bandgap gradient is regulated through the Se content gradient along the depth profile of Sb2(S1−xSex)3. Besides, an increasing Se content profile provides an additional built‐in electric field for boosting hole charge carrier collection. Thus, the high charge carrier generation rate leads to a 17.96% improvement in the conversion efficiency compared with a conventional cell. This work may pave the way to boost the conversion efficiency of antimony chalcogenides‐based solar cells to their theoretical limits.

Regulating Energy Band Alignment via Alkaline Metal Fluoride Assisted Solution Post‐Treatment Enabling Sb2(S,Se)3 Solar Cells with 10.7% Efficiency

“…Obviously, due to the NaF-SPT process can amend the steep grading of S/Se into a mild one as seen in Figure 2d,e, a more spatially flat VBM structure can generate, [27,28] whereas the steep S/Se distribution in the control sample would introduce an internal force that opposes hole transport. Furthermore, when the light of different wavelengths is incident concurrently from ETL to the Sb 2 (S,Se) 3 layer, the absorption capacity of the absorber gradually decreases with the increasing wavelength of light, [27] resulting in a gradually decreasing carrier migration rate. These results imply that a large number of holes in control devices cannot reach HTL, resulting in serious recombination losses.…”

High‐Efficiency Sb2(S,Se)3 Solar Cells with New Hole Transport Layer‐Free Back Architecture via 2D Titanium‐Carbide Mxene

“…[ 5,6 ] The short carrier lifetime, complicated deep defects, and interface recombination are primarily responsible for poor device performance. [ 7,8 ] Among them, one of the crucial variables is severe recombination at the back contact interface, which is significantly dependent on the quality of the Sb 2 (S,Se) 3 /back contact materials (BCMs) interface. Hence, a careful selection of BCMs is necessary to fully realize the potential of Sb 2 (S,Se) 3 solar cells.…”

“…Besides, for another side of the back contact interface, the composition (S/Se ratio) of Sb 2 (S x Se 1− x ) 3 thin film will essentially affect its surface chemistry and energy level, which complicates the band alignment of the back contact interface of devices. [ 18,19 ] But, the reported WF of carbon and Au BCMs are relatively fixed, which will not meet the needs of the versatile back contact interface regulation. Therefore, it is urgent to develop green, stable, low‐cost, and WF adjustable BCMs for the exploration of highly efficient Sb 2 (S,Se) 3 solar cells.…”

Highly efficient BiVO4 single-crystal nanosheets with dual modification: phosphorus doping and selective Ag modification

“…Energy-environmental catastrophes elicited via soaring population and hasty industrialization are the foremost tribulations of the past decade. In this regard, photocatalysts has evolved as a revolutionary and sustainable resolution [4][5][6][7]52]. BiVO 4 as a visible-light response photocatalyst has shown tremendous potential for hydrogen evolution and degradation of organic pollutants because of abundant raw material sources, good stability, low cost, and narrow band gap [8,9,20,36,39].…”