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本文在紧束缚近似的基础上,考虑了Ando处理二维多体问题时来用的Hohenberg-Kohn-Sham局域密度泛函理论,计算了一种具有锯齿形式的新型材料Si-nipi多层结构系统的电子基态和激发态.计算结果表明,在同样的掺杂浓度和外界激发下,Si-nipi材料比GaAs-nipi材料的有效能隙更窄,低亚导带间能量间隔随自由载流子浓度n~(2)变化的速率是GaAs-nipi 材料相应值的 1/2.当选择n_D=n_A=1.85 ×10~(19)cm~(-3),d=400A以及 d_n=d_p=40A时,可使有效能隙E_(?)~(eff,si)在0.1-0.2eV之间变化.从理论上证明了,Si掺杂超晶格可成为一种具有可变载流子浓度和可变能隙的新型人造材料.
On the basis of tight binding approximation, this paper considers the Hohenberg-Kohn-Sham local density functional theory that Ando uses to deal with two-dimensional multi-body problems, and calculates a new type of Si-nipi multilayer structure with serrated form The electronic ground state and the excited state of the system are calculated.The calculated results show that the Si-nipi material has a narrower effective energy gap than the GaAs-nipi material with the same doping concentration and external excitation, The rate of change of the concentration n ~ (2) is 1/2 of the corresponding value of GaAs-nipi. When n_D = n_A = 1.85 × 10 ~ (19) cm -3, d = 400A and d_n = d_p = 40 A, the effective energy gap E _ (~) ~ (eff, si) can be varied from 0.1 to 0.2 eV.It has been theoretically proved that the Si-doped superlattice can be a kind of quantum well with a variable carrier concentration And a new energy-variable gap artificial materials.