TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The average mole ratio of Se:S in the monolayer shell is 3:1-10:1. The core further comprises a Group II metal. The core comprises a compound selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, and InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, AlGaN, AlGaP, AlGaAs, AlGaSb, InGaN, InGaP, InGaAs, InGaSb, AlInN, AlInP, AlInAs, and AlInSb, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs and/or InAlPSb. The Group II metal is selected from Zn, Cd, Hg and/or Mg. The nanocrystal further comprises at least one additional monolayer comprising the compound (I) on the monolayer shell; at least two additional monolayers each comprising the compound (I) on the ZnSeS monolayer shell. The additional monolayers each comprise Se and S and have a Se:S concentration ratio gradient between the additional monolayers. The Se:S concentration ratio gradient of the additional monolayers comprises an increasing concentration of S and decreasing concentration of Se in a direction away from the core. The concentration ratio gradient of the additional monolayers comprises an increasing concentration of Se and decreasing concentration of S in an direction from the additional monolayer closest to the core to an additional monolayer farther from the core; and decreasing concentration of Se and an increasing concentration of S in a direction from the additional monolayer farther from the core to an additional monolayer farthest from the core. The nanocrystal comprises an outermost layer comprising ZnS. The core comprises InP; InZnP. The nanocrystal has a full width at half maximum of less than or equal to 45 nm; has a luminous efficiency (QY) of greater than or equal to 70%; has a diameter of greater than or equal to 6 nm; has a light emitting region of 500-750 nm. The Zn, Se, and S precursors are present in a mole ratio of 1:2-60:1 to form the monolayer shell having a Se:S mole ratio of 2:1-20:1. Preferred Method: The method further involves: forming at least one additional monolayer comprising the compound (I) on the monolayer shell. The additional monolayer is formed by introducing an additional Se precursor and additional S precursor. The additional ZnSeS monolayer is formed by further introducing an additional Zn precursor. The forming step involves: forming at least two additional monolayers, each comprising the compound (II). The forming at least two additional monolayers involves: introducing an additional Se and S precursor in a mole ratio such that the additional monolayers have a Se:S concentration ratio gradient; introducing an additional Zn, Se and S precursor in a mole ratio such that the additional monolayers have a Se:S concentration ratio gradient. The method further involves: forming an outermost layer comprising ZnS. EXAMPLE - InP Core was prepared as follows: 0.058 g Indium acetate, 0.154 g palmitic acid, and 10 ml 1-octadecene were added to a flask and vacuum-treated at 120 degrees C for one hour. The mixture was heat-treated up to 280 degrees C after introducing nitrogen (N2) into the flask. When the reactant was stabilized by setting the reaction temperature at 280 degrees C, a mixed solution of 29 mu l tris(trimethylsilyl)phosphine and 0.5 ml trioctyl phosphine (TOP) was rapidly added to it. The resulting mixture was reacted for 40 minutes. In addition, 0.058 g Indium acetate, 0.154 g palmitic acid, and 4 m 1-octadecene were added to another flask, vacuum-treated at 120 degrees C for 1 hour, and cooled down to 50 degrees C. After introducing nitrogen (N2) into the flask, a mixed solution of 29 mu l tris(trimethylsilyl)phosphine and 0.5 ml TOP was added to the first InP mixed solution in a dropwise fashion for 15 minutes. The resulting mixture was further reacted for 10 minutes. The obtained InP nanocrystal quantum dot (QD) had a UV first absorption maximum of 565-575 nm. InP/ZnSeS/ZnS nanocrystal was prepared as follows: 0.056 g zinc acetate, 0.189 g oleic acid, and 10 ml trioctylamine were added to a flask and vacuum-treated at 120 degrees C for 10 minutes. The vacuum-treated mixture was heated up to 180 degrees C when introducing nitrogen in the flask. Next, the prepared InP core and 0.03 mmol Se/TOP were added to it within 10 seconds. The resulting mixture was heated up to 280 degrees C. Then, 0.005 mmol of S/TOP was added to the heated mixture. The obtained mixture was then heated up to 320 degrees C and reacted for 20 minutes. Next, a mixed solution of 0.02 mmol of Se/TOP and 0.01 mmol of S/TOP was slowly injected to it. The resulting mixture was reacted for 20 minutes. This same step was repeated by switching a mixing ratio of Se and S. The mixed solution was prepared by respectively mixing 0.01 mmol Se/TOP and 0.05 mmol of S/TOP, 0.005 mmol of Se/TOP and 0.15 mmol of S/TOP, 0.005 mmol of Se/TOP and 0.2 mmol of S/TOP, and 0.2 mmol of a S/TOP solution, which were sequentially used. When the reaction was complete, the reactor was cooled down, and the InP/ZnSeS nanocrystal was centrifuged with ethanol and dispersed into toluene. In addition, 0.056 g zinc acetate, 0.0947 g oleic acid, and 10 ml trioctylamine were added to a flask and vacuum-treated at 120 degrees C for 10 minutes. The vacuum-treated mixture was heated up to 220 degrees C after substituting nitrogen into the flask. The InP/ZnSeS nanocrystal toluene solution was added to the flask within 10 seconds, and 6 mmol of S/TOP was slowly injected into. The resulting mixture was heated up to 280 degrees C and reacted for 2 hours. The obtained nanocrystal (QD) had a UV first absorption maximum of 585-595 nm, a PL light emitting peak of 615-625 nm, and a full width at half maximum (FWHM) ranging from 40-45 nm. In addition, the nanocrystal (QD) had luminous efficiency (QY) of 70%.