Colloidal quantum rods and wells for lighting and lasing applications

Colloidal semiconductor nanocrystals, also known as "quantum dots" (QDs), represent an example of a disruptive technology for display and lighting applications. Their high luminescence efficiency and tunable, narrow emission are nearly ideal for achieving saturated colors and enriching the display or TV color gamut. Our contribution will discuss the next generation of inorganic nanostructures with electronic structure optimized for achieving emission characteristics beyond traditional near-spherical QDs. For example, nano-heterostructures with spherical CdSe QDs epitaxially integrated into CdS quantum rods combine high luminescence efficiency with giant extinction coefficients, large Stokes shifts, and linearly polarized emission. Such a set of characteristics can be ideal for LCD backlighting. The other class of emitters includes colloidal quantum wells (QWs) whose ensemble luminescence is significantly narrower than emission spectra of the best QD samples. Moreover, we show that colloidal QWs produce amplified spontaneous emission (ASE) with pump-fluence thresholds as low as 6 μJ/cm² and gain as high as 600 cm^-1, on par with the best values for any solution-processed material.