Tandem solar cells based on quantum dots

Abstract

Establishing tandem photovoltaic device structures to achieve full-spectrum utilization of solar energy is a vital pathway to maximizing the power conversion efficiency (PCE). The dominant photovoltaic materials currently available (including silicon, perovskite, and organic semiconductors) are restricted by their bandgaps. They are only capable of utilizing the photon energy in the solar spectrum that is less than ∼1100 nm. This limits the potential for further enhancements in device efficiency. Meanwhile, at present, the production process for infrared photovoltaic materials, represented primarily by III–V group semiconductors, is complex and costly, constraining their application in the field of civilian photovoltaic cells. Lead chalcogenide (PbX, X = S, Se) quantum dots (QDs) exhibit strong quantum confinement effects, and their bandgap can cover the entire infrared spectrum of solar light by adjusting their size. They can also be prepared through a solution process, denoting them as highly promising low-cost infrared photovoltaic materials. These are anticipated to serve as bottom cell materials in the construction of efficient, low-cost, tandem solar cells. In this paper, we provide a comprehensive summation of the latest research progress and challenges concerning various tandem solar cells based on QD materials (including QD/QD, organic/QD, and perovskite/QD). We aspire to highlight the immense potential of low-bandgap QD photovoltaic materials in the development of high-efficiency, stable, and cost-effective solar cells.