Size-tunable infrared (1000-1600 nm) electroluminescence from solution-processible PbS quantum dot nanocrystals: Towards monolithic optoelectronic integration on silicon

This article reviews devices fabricated using room-temperature solution-casting compatible with silicon post-processing, which produce communications-wavelength electroluminescence. Integrable optoelectronics may be facilitated in this processible material system - one which may conveniently be combined with silicon electronics, passive optics, and RF platforms. Synthetic conditions determine nanocrystal diameter and thereby tune, through the quantum size effect, the spectrum of optical emissions from the quantum dots. It is shown that it is possible to span across and beyond the 1.3-1.6 μm spectrum of optical communications. Nonradiative recombination from the nanocrystals' surface is addressed by choosing stabilizing, passivating organic ligands which nevertheless permit energy transfer from polymer to nanocrystals. Experimental determination of the efficiency of excitation transfer from the polymer matrix to dots, a key factor in increasing device electroluminescence efficiency, is described.