CAJ | 학술논문

将纳米硅薄膜看成理想的一维限制的量子面结构，通过第一性原理计算研究了不同厚度的硅(111)量子面的能带结构及态密度。随着量子面厚度的变化，在 Si-H 键钝化较好的量子面结构上，其带隙宽度变化主要遵循量子限制效应规律。当在表面掺杂时，模拟计算表面含 Si-N 键的硅(111)量子面的结果表明：在一定厚度范围内，带隙宽度主要由量子限制效应决定；超过这个厚度，带隙宽度同时受量子限制效应和表面键合结构的影响。保持量子面厚度不变，表面掺杂浓度越大则带隙变窄效应越明显。同样，模拟计算含 Si-Yb 键的硅(111)量子面的结果也有同样的效应。几乎所有的模拟计算结果都显示：量子面的能带结构均呈现出准直接带隙特征。
장납미규박막간성이상적일유한제적양자면결구，통과제일성원리계산연구료불동후도적규(111)양자면적능대결구급태밀도。수착양자면후도적변화，재 Si-H 건둔화교호적양자면결구상，기대극관도변화주요준순양자한제효응규률。당재표면참잡시，모의계산표면함 Si-N 건적규(111)양자면적결과표명：재일정후도범위내，대극관도주요유양자한제효응결정；초과저개후도，대극관도동시수양자한제효응화표면건합결구적영향。보지양자면후도불변，표면참잡농도월대칙대극변착효응월명현。동양，모의계산함 Si-Yb 건적규(111)양자면적결과야유동양적효응。궤호소유적모의계산결과도현시：양자면적능대결구균정현출준직접대극특정。
We regard the nanocrystalline silicon films as an ideal one-dimensional quantum limiting surface structure, and study the band structure and density of states of the different thickness silicon (111) quantum surface by the first-principles calculation. As the change of the thickness of the quantum surface well passivated by Si-H bond, the band gap mainly follow the quantum confine-ment effect. When the silicon (111) quantum surface contains Si-N bond, the simulated results show that the band gap is mainly determined by the quantum confinement effect in a certain range of thickness, but beyond the thickness, the band gap is determined by both the quantum confinement effect and bond structure. While maintaining a constant thickness, the greater doping concentration of the quantum surface, the more obvious the band gap narrowing effect. Similarly, the simulated result of silicon (111) quantum surface which contain Si-Yb has the same effect. It is worth noting that almost all of the simulated results show that the band structures of the quantum surface show quasi-direct band gap characteristics.