Properties of semiconductor colloidal quantum dots obtained under controlled synthesis conditions

The influence of the technological parameters of synthesis on the structural and physical properties of colloidal quantum dots based on lead sulfide, indium antimonide, and cadmium selenide has been investigated. The use of a solvent nonsolvating for the metalloid precursor allows one to obtain a slow, controlled process and trace in detail all stages of crystallization of nanoparticles – nucleation and growth, Ostwald ripening, uncontrolled growth. It is possible to obtain crystallites of perfect structure and size with minimal scatter – no more than $\pm$ 10%. It was found that the maximum sizes of nanoparticles are limited by the thermodynamic growth conditions and have a value of about 5 nm. In addition, quantum dots exhibit a number of specific properties – anomalous temperature dependence of photoluminescence and instability of the current-voltage characteristic, which are explained in the size quantization model of the energy and momentum of nonequilibrium electrons. For different variants of semiconductors, the features become more pronounced with an increase in the size quantization parameters.