LiNiMnCoO (NMC811) is a popular cathode material for Li-ion batteries, yet degradation and side reactions at the cathode-electrolyte interface pose significant challenges to their long-term cycling stability. Coating LiNiMnCoO (NMC) with refractory materials has been widely used to improve the stability of the cathode-electrolyte interface, but mixed results have been reported for AlO coatings of the Ni-rich NMC811 materials. To elucidate the role and effect of the AlO coating, we have coated commercial-grade NMC811 electrodes with AlO by the atomic layer deposition (ALD) technique.
View Article and Find Full Text PDFColloidal quantum dots (CQDs) are finding increasing applications in optoelectronic devices, such as photodetectors and solar cells, because of their high material quality, unique and attractive properties, and process flexibility without the constraints of lattice match and thermal budget. However, there is no adequate device model for colloidal quantum dot heterojunctions, and the popular Shockley-Quiesser diode model does not capture the underlying physics of CQD junctions. Here, we develop a compact, easy-to-use model for CQD devices rooted in physics.
View Article and Find Full Text PDFp-Type doping in Cu(I)-based semiconductors is pivotal for solar cell photoabsorbers and hole transport materials to improve the device performance. Impurity doping is a fundamental technology to overcome the intrinsic limits of hole concentration controlled by native defects. Here, we report that alkali metal impurities are prominent p-type dopants for the Cu(I)-based cation-deficient hole conductors.
View Article and Find Full Text PDFA cost-effective, vacuum-free, liquid-metal-printed two-dimensional (2D) (∼1.9 nm-thick) tin-doped indium oxide (ITO) thin-film transistor (TFT) was developed at the maximum process temperature of 200 °C. A large-sized 2D-ITO channel layer with an electron density of ∼1.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2021
Atomically thin oxide semiconductors are significantly expected for next-generation cost-effective, energy-efficient electronics. A high-performance p-channel oxide thin-film transistor (TFT) was developed using an atomically thin p-type tin monoxide, SnO channel with a thickness of ∼1 nm, which was grown by a vacuum-free, solvent-free, metal-liquid printing process at low temperatures, as low as 250 °C in an ambient atmosphere. By performing oxygen-vacancy defect termination for the bulk-channel and back-channel surface of the ultrathin SnO channel, the presented p-channel SnO TFT exhibited good device performances with a reasonable TFT mobility of ∼0.
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