Silicon carbide (SiC) is used in a variety of applications including photovoltaic due to its high stability. The wide bandgap of SiC limits these applications and necessitates bandgap tuning toward lower energy for efficient solar absorption. In this regard, the electronic properties of highly stable SiC polytype 6H-SiC are studied by first-principles calculations. By varying the Si composition of 6H-SiC the electronic properties are tailored. The calculated results show that increasing the Si composition of 6H-SiC from 50% to 66.66% reduces the bandgap from 2.98 to 1.54 eV. It is observed that this reduction in bandgap occurs due to the addition of extra Si s/p orbitals which close the conduction band and valance band. From the electronic conductivity calculations, it is found that with increasing Si composition of 6H-SiC the conductivity is improved due to higher hole density which can be verified by the spectrum peaks shifted toward near-infrared and visible region.

中文翻译：

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通过第一性原理计算定制不同硅成分的 6H-SiC 电子性能


碳化硅 (SiC) 由于其高稳定性而被用于包括光伏在内的多种应用。 SiC 的宽带隙限制了这些应用，并且需要将带隙调整为更低的能量以实现高效的太阳能吸收。在这方面，通过第一性原理计算研究了高度稳定的SiC多型6H-SiC的电子特性。通过改变 6H-SiC 的 Si 成分，可以定制电子特性。计算结果表明，将 6H-SiC 的 Si 成分从 50% 增加到 66.66%，带隙从 2.98 eV 降低到 1.54 eV。据观察，带隙的这种减小是由于添加了额外的 Si s/p 轨道而导致导带和价带闭合。从电子电导率计算发现，随着6H-SiC中Si成分的增加，由于空穴密度更高，电导率得到提高，这可以通过向近红外和可见光区域移动的光谱峰来验证。