Electronic Structure of Single-Crystal CaF₂(111) with Nanoscale Phases of Ca and Si  

作　　者：Yokub Suvonovich Ergahov Boltakhodja Ermatovich Umirzakov Gulmira Khalmuratovna Allayarova 

机构地区：[1]Department of Technology of Electronic Devices Generating, Tashkent State Technical University, Tashkent, Uzbekistan

出　　处：《Materials Sciences and Applications》2018年第12期965-971,共7页材料科学与应用期刊（英文）

摘　　要：The impact of Ca and Si nano-scale structures on parameters and density of states of single-crystalline CaF2(111) was studied. It was shown that at low concentration of ions of Ar+ (D ≤ 5 × 1015 cm-2) one witnesses formation of nanoscale phases on CaF2 surface. It was revealed that these phases lead to narrowing of the forbidden band Еg between the phases by 4 - 4.5 eV. At higher concentrations (D ≈ 6 × 1016 cm-2) the surface completely is covered by Ca atoms. It was shown that deposition of θ = 10 thick Si single layer on CaF2 surface manifests island picture. The concentration of Ca and Si nano-scale phases on the surface of CaF2 and the band gap of the phases were investigated as a function of (hν) of passing light. Nano-scale phases and nano-scale films of Ca were obtained by using the technique of bombardment with ions of Ar+ of CaF2 surface. Formation of nano-scale phases were accompanied by change in the composition and structure of CaF2 zones located between the phases. These changes led to narrowing of the forbidden band of CaF2 down to 7.5 - 8 eV. The concentration of Ca and Si nano-scale phases on the surface of CaF2 and the band gap of the phases were investigated as a function of (hν) of passing light.The impact of Ca and Si nano-scale structures on parameters and density of states of single-crystalline CaF2(111) was studied. It was shown that at low concentration of ions of Ar+ (D ≤ 5 × 1015 cm-2) one witnesses formation of nanoscale phases on CaF2 surface. It was revealed that these phases lead to narrowing of the forbidden band Еg between the phases by 4 - 4.5 eV. At higher concentrations (D ≈ 6 × 1016 cm-2) the surface completely is covered by Ca atoms. It was shown that deposition of θ = 10 thick Si single layer on CaF2 surface manifests island picture. The concentration of Ca and Si nano-scale phases on the surface of CaF2 and the band gap of the phases were investigated as a function of (hν) of passing light. Nano-scale phases and nano-scale films of Ca were obtained by using the technique of bombardment with ions of Ar+ of CaF2 surface. Formation of nano-scale phases were accompanied by change in the composition and structure of CaF2 zones located between the phases. These changes led to narrowing of the forbidden band of CaF2 down to 7.5 - 8 eV. The concentration of Ca and Si nano-scale phases on the surface of CaF2 and the band gap of the phases were investigated as a function of (hν) of passing light.

关 键 词：NANO-SCALE Band Gap Hetero-Structures Surface BOMBARDMENT 

分 类 号：O6[理学—化学]