Nanostructured double perovskite for solar energy conversion devices (NanoSEC)

Finance by: The Executive Agency for Higher Education, Research, Development and Innovation Funding (UEFISCDI, P1 – Development of the national CD system, Project type: Research projects to stimulate young independent teams (TE)

Contract nr. TE 11/ 05.05.2020
CODE: PN-III-P1-1.1-TE-2021-0265

Implementation period: 15.05.2022 – 14.05.2024
Contract value: 445,715.00 lei
Project Manager: Andreea Georgiana BULAI

The overall aim of the project

The main objective of NanoSEC project is to obtain new devices with high solar energy conversion efficiency, competitive with the commercialized photonic components, thus bringing an important contribution in solving the increasing environmental crises caused by fossil fuel usage.

Abstract

The research interest in methods and materials for clean energy generation and storage in a sustainable manner is driven by the rapidly growing global energy demand and the negative effect of greenhouse gasses. Converting solar energy in electricity and fuel is the main focus of renewable energy research. The world’s photovoltaic capacity of the existing technologies is still limited. Due to the intermittent nature of sunlight, a separate energy storage mechanism which is effective and environmentally harmless is required for solar energy to fully replace fossil energy. This makes photoelectrochemical cell an interesting alternative. The present proposal addresses these concerns for renewable energy production and storage by designing new nanostructured systems that are based on double oxide ferroelectric materials, for which recently reported experimental results and theoretical studies showed promising characteristics. High quality absorbing materials with structural, optical and ferroelectric properties that efficiently convert the solar energy into electricity will be obtained using new experimental configurations based on pulsed laser deposition and high power impulse magnetron sputtering. Also, different cell architectures with multi-layered configurations are considered. The achievement of this project general objective will bring significant contribution to the sustainability and future commercialization of photonic devices as sources of renewable energy.

 The project team:

1. Georgiana BULAI , CS III, ICI-DSESN
2. Vasile TIRON, CS II, ICI-DSESN
3. Felicia GHEORGHIU, CS III, ICI-DSESN
4. Adrian BORHAN, Teaching assistant, Faculty of Chemistry
5. Francisca HUSANU, PhD student, Faculty of Physics

The scientific achievements of the project were based on the synthesis of thin film with structural, optical and piezoelectric/ferroelectric properties optimized that promote their use in high efficiency solar energy conversion devices. This was achieved by using two thin film deposition methods: pulsed laser deposition and magnetron sputtering (especially high-power impulse magnetron sputtering – HiPIMS). The analysis results highlighted how the structural, chemical, optical and electrical properties of the samples were influenced by the varied experimental parameters. Thus we were able to identify the optimal deposition conditions (related to the temperature and nature of the substrate, pressure and composition of the mixed gas introduced into the deposition chamber, characteristics of the magnetron discharge pulse) to obtain a thin crystalline layer with small band gap and high ferroelectric response. The applicability of the as obtained samples in solar energy conversion devices was evaluated by analyzing the current-voltage characteristic and by monitoring the degradation of different dyes through photo-, piezo- and photo-piezocatalytic experiments.

A major achievement was the development of a method used to obtain chromium-doped bismuth ferrite-based thin films with controllable chemical composition and structure by adjusting the HiPIMS pulse configuration. This procedure was described in the national patent proposal no. A 2023/00781/04.11.2023 submitted to OSIM. The method involves the deposition of thin films on a glass substrate covered by a conductive layer of fluorine doped tin oxide, using a Bi2FeCr alloy as the source material and a mixture of argon and oxygen as working gas. The process consists in the differential acceleration of the ionic species present in the discharge plasma (and thus changing the amounts of bismuth, iron and chromium in the deposited thin film) by adjusting the amplitude, duration and delay time of the positive voltage pulse. This selective acceleration can also be applied for thin films of dielectric materials deposited on insulating, electrically isolated or grounded substrates. With the change in chemical composition, both structural and ferroelectric properties are modified.

Within the project, we evaluated the performance of thin films based on bismuth ferrite with Cr addition in the photocatalytic water splitting process for efficient oxygen production. This approach is crucial in the development of renewable technologies for the production of green fuels, such as oxygen generation, with significant implications in energy and sustainability. The scientific impact can be quantified through the publication of three articles and the submission of one paper in Web of Science indexed journals with a high impact factor (areas Q1 and Q2) and through 5 international conference participations were the main obtained results were presented.