High efficiency perovskite quantum dot solar cells with charge separating heterostructure

• Published in: Nature communications Vol. 10; no. 1; pp. 2842 - 8
• Main Authors: Zhao, Qian, Hazarika, Abhijit, Chen, Xihan, Harvey, Steve P., Larson, Bryon W., Teeter, Glenn R., Liu, Jun, Song, Tao, Xiao, Chuanxiao, Shaw, Liam, Zhang, Minghui, Li, Guoran, Beard, Matthew C., Luther, Joseph M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 28.06.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 140/125; 140/146; 639/301/299/946; 639/301/357/1017; Composition; Computer architecture; Harvesting; Heterojunctions; Heterostructures; Humanities and Social Sciences; MATERIALS SCIENCE; Metal halides; multidisciplinary; Optoelectronics; Performance enhancement; Perovskites; Photovoltaic cells; Photovoltaics; Quantum dots; Science; Science (multidisciplinary); Solar cells; SOLAR ENERGY; Stability; Thin films
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-10856-z

Metal halide perovskite semiconductors possess outstanding characteristics for optoelectronic applications including but not limited to photovoltaics. Low-dimensional and nanostructured motifs impart added functionality which can be exploited further. Moreover, wider cation composition tunability and tunable surface ligand properties of colloidal quantum dot (QD) perovskites now enable unprecedented device architectures which differ from thin-film perovskites fabricated from solvated molecular precursors. Here, using layer-by-layer deposition of perovskite QDs, we demonstrate solar cells with abrupt compositional changes throughout the perovskite film. We utilize this ability to abruptly control composition to create an internal heterojunction that facilitates charge separation at the internal interface leading to improved photocarrier harvesting. We show how the photovoltaic performance depends upon the heterojunction position, as well as the composition of each component, and we describe an architecture that greatly improves the performance of perovskite QD photovoltaics. Metal halide perovskites have wide tunability in both material and device structure. Here Zhao et al. fabricate heterojunctions of colloidal perovskite quantum dots with different composition using layer-by-layer deposition and demonstrate improved photovoltaic performance with enhanced photocarrier harvesting.