Semiconductor nanocrystals (NCs) are interesting optical materials that have been explored for a range of applications such as light emitting diodes (LEDs), photovoltaic cells, lasers and biologic markers. For practical optical uses heterostructured NCs with thick shells (“giant NCs”) offer the advantage of supressed photoluminescence intermittency and reduced rates of Auger recombination. Giant NCs with proper structures can present simultaneous two-colour emission, due to core and shell states [1-2]. These NCs can be convenient for example in very accurate and self-calibrating nanosystems.