Breaking the Size Limitation of Directly‐Synthesized PbS Quantum Dot Inks Toward Efficient Short‐wavelength Infrared Optoelectronic Applications

Abstract

PbS quantum dots (QDs) are promising building blocks for solution‐processed short‐wavelength infrared (SWIR) devices. The recently developed direct synthesis of semi‐conductive PbS QD inks has substantially simplified the preparation processing and reduced the material cost, while facing the challenge to synthesize large‐size QDs with absorption covering the SWIR region. Herein, we for the first time realize a low‐cost, scalable synthesis of SWIR PbS QD inks after an extensive investigation of the reaction kinetics. Finally, based on these PbS SWIR QD inks, the solar cell demonstrates a record‐high power conversion efficiency (PCE) of 1.44 % through an 1100 nm cutoff silicon filter and the photodetector device shows a low dark current density of 2×10−6 A cm−2 at −0.8 V reverse bias with a high external quantum efficiency (EQE) of 70 % at ≈1300 nm. Our results realize the direct synthesis of low‐cost and scalable SWIR QD inks and may accelerate the industrialization of consumer SWIR technologies.

Tandem solar cells based on quantum dots

“…48,49 The recent development of direct synthesis methods for QD semiconductor inks has significantly reduced their production costs, making them highly suitable for industrial-scale applications. 37,[50][51][52][53][54][55] Consequently, PbX QDs emerge as ideal low-cost narrow-bandgap photovoltaic material, holding promise as bottom cell materials for the fabrication of low-cost, high-efficiency, and highly stable tandem solar cells.…”

PbS Quantum Dots Ink with Months‐Long Shelf‐Lifetime Enabling Scalable and Efficient Short‐Wavelength Infrared Photodetectors

“…[10,11] Therefore, these QDs have been intensively studied as building blocks for solar cells, [12][13][14][15] light-emitting diodes, [16][17][18][19] light-emitting transistors, [20,21] and photodetectors. [22][23][24][25] The obvious advantages notwithstanding, the utilization of PbS QDs for SWIR photodetection still faces several technical challenges. Assynthesized PbS QDs are commonly passivated with oleic acid (OA) ligands, which control the kinetics of nucleation and growth.…”

Eco-friendly and ultrathin solar cells featuring nanocrystals: advances and perspectives

“…15 Quantum dots are partially composed of the II-VI (for example, CdS, CdSe, CdTe, and ZnS) and IV-VI (for example, PbS and PbSe) group nanocrystals with the characteristics of the surface effect and the quantum confinement effect, and have great application potential in the fields of optoelectronics and biofluorescent labeling. [16][17][18][19][20][21] Nevertheless, these nanocrystal materials with heavy metals, e.g., lead and cadmium, are extremely hazardous when present in the water supply or the atmosphere. In recent years, abundant research attention has been focused on the environmentally friendly I-III-VI, I-V-VI, and I-VI group nanocrystal solar cells.…”