Understanding photochemical charge separation in Sb2S3 films for solar-driven H2 generation and photovoltaic cells application

• Grant number: 23/12724-5
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: February 01, 2024
• End date: January 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Edson Antonio Ticianelli
• Grantee: Moisés Albuquerque de Araújo
• Supervisor: Frank Erich Osterloh
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: University of California, Davis (UC Davis), United States
• Associated to the scholarship: 21/01268-3 - Surface modifications of nanostructured thin films of copper sulphide: a novel approach to improve hydrogen gas generation and carbon dioxide reduction, BP.PD

Abstract

Solar energy conversion systems, such as photoelectrochemical (PEC) and photovoltaic cells, have stood out as an environment-friendly approach to obtaining the two most popular energy carriers in our lives, i.e., fuel and electricity. To become the mainstream way of achieving energy, the semiconductor materials employed in these systems must absorb solar energy in an effective manner as well as feature an efficient process of charge carriers' generation, separation, and transportation. Among the semiconductor materials being considered, antimony(III) sulphide (Sb2S3) has recently gained considerable attention for application in PEC/photovoltaic cells due to its unique optoelectronic properties and anisotropic charge transfer behaviour, i.e., the photogenerated charge carriers transportation is more efficient along the [hk1] direction. Despite these advantages, electron-hole recombination is a limiting factor for the aforementioned applications. Herein, we aim to address this issue by obtaining a stacked multilayer system comprised of NiOx/([hk1]-oriented Sb2S3)/(In2S3 or ZnS), which has suitable band alignment that favours charge carriers separation and transportation. To obtain an in-depth understanding of these photo-induced charge carriers processes and evaluate the effect of the presence of defects in the multilayer system, we employ surface photovoltage spectroscopy, which is a technique uniquely found at the Osterloh Group at UC Davis. The resulting multilayer system will be fabricated by economical solution-processed deposition methodologies (i.e., spin-coating/electrodeposition/chemical bath deposition) and will be applied for H2 generation via solar-driven water splitting and photovoltaic cells. Overall, this work features novel strategies to further push towards the commercial application of Sb2S3 films in solar energy conversion technologies. (AU)