ZnO is a wide direct band gapⅡ-Ⅵ semiconductor material with a large exciton binding energy of 60 meV at room temperature

more larger than the ionization energy at room temperature(26 meV)

so ZnO is a suitable high efficient ultraviolet material.ZnO quantum dots has unique photoelectric properties

especially can be used in UV laser devices related with the exciton characteristic

therefore

it is very important to study the ground state properties of exciton of ZnO quantum dots in theory.We compared the calculation results with the experiment values that indicate the new trial wave function is right.We also calculated the variation parameter

K

e

and

K

h

the normalization constant

N

e

and

N

h

as functions of

r

and the trial wave function ψ as functions of a

B

.The results indicate when the radius of the quantum dot is very small(

r

≤4.0a

B

)

the trial wave function ψ will have a rapid change.And meanwhile the quantum dot will have a larger surface to volume ratio.So the surroundings

the defects and the purities will have strong effects on the ground state properties of the quantum dot

while the medium on the surface(or the interface) will have effects too.Thus

it is very important to reduce the defects and the dangling bonds on surface

eliminate the non-radiative recombination and the surface(the interface) emission by effective doping and modifying.