This paper reviews recent progress in the synthesis of near-infrared (NIR) lead chalcogenide (PbX; PbX=PbS, PbSe, PbTe) quantum dots (QDs) and their applications in NIR QDs based light emitting diodes (NIR-QLEDs). It summarizes the strategies of how to synthesize high efficiency PbX QDs and how to realize high performance PbX based NIR-QLEDs.
Chinese Physics BCompared with the development of visible colloidal QDs, the development process of nearinfrared (NIR) QDs is relatively slow because of the challenges, such as lacking of effective synthesis method and characterization techniques. Due to the above-mentioned advantages, NIR QDs show great potential and promise in many applications. Apart from the applications in optoelectronic devices, NIR QDs are also widely employed in interdisciplinary domains including their acting as optical amplifier medium for electrical communication systems, [12] as remote sensing or as fluorescent materials for biomedical imaging, labeling and sensing. [13][14][15] Among all types of the NIR QDs that had already been found, [6] the lead chalcogenide QDs (PbX; PbX=PbS, PbSe, PbTe) in IV-VI group have shown the great promise both in fundamental scientific research and in technological applications, as they have narrow bulk bandgaps (0.41 eV, 0.278 eV and 0.31 eV at room temperature, respectively) along with broadband absorption, large excitonic Bohr radii (due to the high dielectric constant and small effective mass of carriers) and multiple exciton generation. [16] Furthermore, their energy bandgap can be widely tuned from about 0.3 eV to >2.0 eV. [12][13][14][15][17][18][19][20] These remarkable and unique properties make the PbX QDs ideal candidates in NIR optoelectronic applications.