One of the model theories for band aligning is average-bond-energy model

in which the average-bond-energy is used as a reference level for determining valence band offsets.Since the model has been proved quite successful in determining band offsets of lattice-matched heterojunctions

here we extended it to study band offsets of strained-layer heterojunctions.Through a careful study of band offset parameter E mv with deformation potential a

mv

we found that the averge band offset parameter

E

mv.av

(

E

mv.av

=

E

m

-E

v.av

) almost kept unchanged under different strain conditions

which is one of the main features of average bond energy method.Therefore

to obtain strained-layer band offset parameter

E

mv

only the unstrained band offset parameter

E

mv.O

deformation potential parameter

b

and the experimental value of spin orbit splitting Δ

0

are necessary for simple algebraic operations.Obviously

it will be very convenient for calculating valence band offsets of strained-layer heterojunctions

since it doesn't need to consider the exact strain characteristics.In addition

we introduced deformation potential of band gap a Gap to describe the change of band gap under different strain states.Based on the relationship between conduction band offset and valence band offset (Δ

E

c

=Δ

E

g

+Δ

E

v

)

it is easy to calculate conduction band offsets of heterojunctions under different strain conditions.Our calculated band offsets of several common strained-layer heterojunctions are fairy good compared to those obtained by CNL or MST method

and in good agreement with experimental data.To sum up

our method is an effective and simple way in determining band offsets of strained-layer heterojunctions.