Crystal Growth Promotion and Defect Passivation by Hydrothermal and Selenized Deposition for Substrate-Structured Antimony Selenosulfide Solar Cells

Abstract

Antimony sulfide-selenide (Sb2(S,Se)3) is a promising light-harvesting material for stable and high-efficiency thin-film photovoltaics (PV) because of its excellent light-harvesting capability, abundant elemental storage, and excellent stability. This study aimed to expand the application of Sb2(S,Se)3 solar cells with a substrate structure as a flexible or tandem device. The use of a hydrothermal method accompanied by a postselenization process for the deposition of Sb2(S,Se)3 film based on the solar cell substrate structure was first demonstrated. The mechanism of postselenization treatment on crystal growth promotion of the Sb2(S,Se)3 film and the defect passivation of the Sb2(S,Se)3 solar cell were revealed through different characterization methods. The crystallinity and the carrier transport property of the Sb2(S,Se)3 film improved, and both the interface defect density of the Sb2(S,Se)3/CdS interface and the bulk defect density of the Sb2(S,Se)3 absorber decreased. Through these above-mentioned processes, the transport and collection of electronics can be improved, and the defect recombination loss can be reduced. By using postselenization treatment to optimize the absorber layer, Sb2(S,Se)3 solar cells with the configuration SLG/Mo/Sb2(S,Se)3/CdS/ITO/Ag achieved an efficiency of 4.05%. This work can provide valuable information for the further development and improvement of Sb2(S,Se)3 solar cells.

Oxygen Content Modulation Toward Highly Efficient Sb2Se3 Solar Cells

“…To determine details regarding the possible defects, the −d C /d ln f versus frequency curves are plotted and shown in Figure a,d. The defect activation energy ( E A ) and carrier emission factor (ξ 0 ) are obtained from the slope and y-axis intercept of the linear fit (shown in Figure b,e). − It is observed that Cell-0 has two defect energy levels, with values of 91.8 and 298 meV (marked as D 1 and D 3 ), whereas there is only one defect energy level of device Cell-135 (186 meV, marked as D 2 ). According to the previous report, D 1 with an activation energy below 100 meV could be assigned to acceptor defects Se Sb1 or Se Sb2 , D 2 could be assigned to V Sb defects, and D 3 could be assigned to defects like V Se2 or V Se3 .…”

Tellurium Doping Inducing Defect Passivation for Highly Effective Antimony Selenide Thin Film Solar Cell

“…In addition, the depletion width of the T2 device (325 nm) is obviously larger than that of the T0 device (278 nm). The collection and extraction of the charge carrier benefit from the wider depletion width [ 21 ]. As revealed in Figure 5 h, the built-in voltage ( V bi ) of the T0 device is 0.42 V, and it increased to 0.69 V for the T2 device.…”

Post‐Annealing Treatment on Hydrothermally Grown Antimony Sulfoselenide Thin Films for Efficient Solar Cells

“…Despite these drawbacks, hydrothermally grown Sb 2 (S, Se) 3 solar cells have shown a promising PCE of 10.7% after tuning the absorber composition and employing post‐deposition annealing. [ 15 ] Particularly, post‐deposition annealing is found to be effective in improving Sb 2 Se 3 and Sb 2 S 3 solar cells [6a,13b,14,16] . Annealing provides a thermodynamic driving force to promote grain growth, reduce internal defects, release the internal stress of the film, and promote compactness and crystallization.…”