A colloidal material including semiconductor nanocrystals of formula AnXm, wherein A is selected from group Ib, IIa, IIb, IIIa, IIIb, IVa, IVb, Va, Vb, VIb, VIIb, VIII, IIb, III, IV or mixtures thereof, X is selected from group Va, VIa, VIIa or mixtures thereof, and n and m are independently a decimal number from 0 to 5. The semiconductor nanocrystals have a quasi 2D structure, wherein the smallest dimension is smaller than the other two dimensions by a factor of at least 1.5 and the faces substantially normal to the smallest dimension consist either of A or X. Also, a semiconducting thin film, an optoelectronic device, a laser, a photovoltaic cell, a diode, a light emitting diode or a display including the colloidal material.