Abstract
Colloidal PbS quantum dots (QDs) are promising candidates for various optoelectronic applications based on solution-processed thin-film techniques. In this work, a versatile layer-by-layer (LBL) spray deposition of the QDs is introduced aiming for a future large-scale fabrication process of optoelectronic devices. As compared to spin-coated QD solids, a smaller inter-dot distance and a better-ordered superlattice stacking behavior of the QDs are found in the spray-deposited QD solids as confirmed by grazing-incidence small-angle X-ray scattering (GISAXS). The spectral mapping combined time-resolved photoluminescence analysis indicates a longer charge carrier lifetime and better order of the energy state distribution of the spray-deposited QD solid comparing with the spin-coated one. Thus, photodetectors based on spray deposition of QD solids demonstrate an excellent device performance, with the responsivity achieving 365.1 A/W and the detectivity reaching up to 1.4 × 1012 Jones under an illumination power of 63.5 μW/cm2 at a wavelength of 1250 nm. The spray-deposited device performances indicate a great potential of spray deposition of large sized QDs in large-scale fabrications for optoelectronics using longer wavelengths.
Original language | English |
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Article number | 105254 |
Journal | Nano Energy |
Volume | 78 |
DOIs | |
State | Published - Dec 2020 |
Keywords
- GISAXS
- Near-infrared photodetector
- PbS quantum Dots
- Spray deposition