Additive-Assisted Hydrothermal Growth Enabling Defect Passivation and Void Remedy in Antimony Selenosulfide Solar Cells.

Antimony selenosulfide (Sb2(S,Se)3) has recently emerged as a promising light-absorbing material, attributed to its tunable photovoltaic properties, low toxicity, and robust environmental stability. However, despite these advantages, the current record efficiency for Sb2(S,Se)3 solar cells significantly lags behind their Shockley-Queisser limit, especially when compared to other well-established chalcogenide-based thin-film solar cells, such as CdTe and Cu(In,Ga)Se2. This underperformance primarily arises from the formation of unfavorable defects, predominately located at deep energy levels, which act as recombination centers, thereby limiting the potential for performance enhancement in Sb2(S,Se)3 solar cells. Specifically, deep-level defects, such as sulfur vacancy (VS), have a lower formation energy, leading to severe non-radiative recombination and compromising device performance. To address this challenge, thioacetamide (TA), a sulfur-containing additive is introduced, into the precursor solution for the hydrothermal deposition of Sb2(S,Se)3. This results indicate that the incorporation of TA helps in passivating deep-level defects such as sulfur vacancies and in suppressing the formation of large voids within the Sb2(S,Se)3 absorber. Consequently, Sb2(S,Se)3 solar cells, with reduced carrier recombination and improved film quality, achieved a power conversion efficiency of 9.04%, with notable improvements in open-circuit voltage and fill factor. This work provides deeper insights into the passivation of deep-level donor-like VS defects through the incorporation of a sulfur-containing additive, highlighting pathways to enhance the photovoltaic performance of Sb2(S,Se)3 solar cells.

Highly Efficient and Stable Iridium Oxygen Evolution Reaction Electrocatalysts Based on Porous Nickel Nanotube Template Enabling Tandem Devices with Solar-to-Hydrogen Conversion Efficiency Exceeding 10.

Ir is one of the most efficient oxygen evolution reaction (OER) catalysts; however, it is also one of the rarest and most expensive elements. Therefore, it is highly desirable to develop Ir catalysts with nanostructures that reduce Ir consumption by maximizing the surface-to-volume ratio without limiting the mass transport of reactants and products of reactions. Ir OER catalysts on a template that consisted of porous nanotubes (PNTs) based on Ni are fabricated. The Ir/Ni PNTs offer multiple benefits, including high catalytic performance (potential of 1.500 V vs. reversible hydrogen electrode (RHE) at an operating current density of 10 mA cm-2 and Tafel slope of 44.34 mV decade-1 ), minimal use of Ir (mass activity of 3273 A g-1 at 1.53 V vs RHE), and facile mass transport through the NT-sidewall pores (stable operation for more than 10 h). The Ir/Ni PNTs are also applied to a tandem device, consisting of a Cu(In,Ga)Se2 -based photocathode and halide perovskite photovoltaic cell, for unassisted water splitting. A solar-to-hydrogen conversion efficiency that exceeded 10% is also demonstrated, which is nearly 1% point greater than when a planar Ir film is used as the anode instead of Ir/Ni PNTs.

Drop-casted Platinum Nanocube Catalysts for Hydrogen Evolution Reaction with Ultrahigh Mass Activity.

Platinum hydrogen evolution reaction (HER) electrocatalysts in the form of nanocubes (NCs) were synthesized at 50 °C by aqueous-based colloidal synthesis and were applied to electrochemical (EC) and photoelectrochemical (PEC) systems by a fast and simple drop-casting method. A remarkable Pt mass activity of 1.77 A mg-1 at -100 mV was achieved in EC systems (fluorine-doped tin oxide/Pt NC cathode) with neutral electrolyte while maintaining low overpotential and Tafel slope. In the Cu(In,Ga)(S,Se)2 (CIGS)-based PEC system, a carefully chosen amount of Pt NC loading to achieve a compromise between the catalytic activity (more Pt NCs) and better light transmittance (fewer Pt NCs) led to a maximum onset potential of 0.678 V against the reference hydrogen electrode. The photoelectrodes with Pt NCs also exhibited good long-term operational stability over 9.5 h with negligible degradation of the photocurrent. This study presents an effective strategy to greatly reduce the use of expensive Pt without compromising the catalytic performance because the drop-casting of Pt NC solutions to form electrocatalysts is expected to waste less raw material than vacuum deposition.