Dr Mingrui He

Kesterite Thin-Film Solar Cells

Kesterite is not only a mineral but also represents a class of compounds utilized in thin-film solar cells. These compounds typically have the chemical formula Cu₂ZnSnS₄ (CZTS) or Cu₂ZnSnSe₄ (CZTSe). Kesterite solar cells are noted for their use of abundant and non-toxic materials, making them an environmentally friendly option in photovoltaic technology. I am engaged in a detailed investigation into the mechanisms underlying the doping/alloying strategy and surface passivation, focusing on their impact on enhancing the device efficiency of kesterite-based solar cells. Simultaneously, my research also encompasses the exploration of novel dopants and passivation agents, specifically tailored for kesterite solar cells.

Perovskite Thin-Film Solar Cells

Perovskite refers to a group of materials sharing a common crystal structure, known as the perovskite structure. In the realm of solar cell technology, perovskite materials are celebrated for their high efficiency and straightforward manufacturing processes. They are particularly renowned in the photovoltaic sector for their rapidly advancing efficiency rates in converting solar energy into electrical power. In my studies, I am addressing the stability challenge inherent in perovskite materials, which currently hinder their commercial viability. This involves employing compositional engineering at the bulk level and enhancing surface quality through passivation techniques. Our goal is to develop stable perovskite structures suitable for both narrow and wide bandgap applications. The fabrication methodology primarily revolves around a two-step process, incorporating an evaporation method for the large-scale fabrication of cells.

Tandem Solar Cells

Tandem solar cells are an innovative approach in photovoltaics, comprising multiple layers of light-absorbing materials. Each layer is engineered to absorb a distinct portion of the solar spectrum. This multilayer composition, often combining materials like silicon with perovskite, enables tandem cells to surpass the efficiency of traditional single-junction solar cells, heralding a new era in solar energy capture. I am engaged in the development of perovskite/Si tandem solar cells, utilizing the stable wide-bandgap perovskite single junctions that have been developed within our research group.

Solar Water Splitting

Solar water splitting is a groundbreaking method where sunlight is harnessed to dissociate water molecules into hydrogen and oxygen. This process is typically carried out using photoelectrochemical cells. The hydrogen generated is a viable clean fuel, making this technology a cornerstone in the pursuit of renewable energy and storage solutions. We are endeavoring to utilize earth-abundant chalcogenide compounds as photocathodes for solar-driven water splitting cells. Our approach includes the development of interface engineering techniques aimed at enhancing the stability of these systems.