We have grown Zn_1−xCd_xO (ZnCdO) thin films by molecular beam epitaxy on α-Al₂O₃ (0001) substrates across the full composition range of 0 ≤ x ≤ 1. The wurtzite phase is observed in the composition x ≤ 0.44 whereas the rocksalt phase is observed for x ≥ 0.58. Within the composition region of 0.44 < x < 0.58, both wurtzite and rocksalt phases co-exist. At the phase transition to RS at x ∼ 0.55, the optical gap increases drastically to >3.0 eV. A large optical gap of 3.0 eV (an intrinsic gap of ∼2.7 eV) is achieved for RS-ZnCdO alloys at x ∼ 0.6. The stability of the RS phase with a low Cd content can be attributed to the low temperature MBE process. The upward shift of the band gap energy is observed in the mixed phase region due to the phase transition, and the largest band gap energy is obtained as 3.27 eV in the WZ (x = 0) and 3.0 eV in RS (x = 0.6) phase. RS-ZnCdO thin films exhibit a low resistivity of 5 × 10⁻⁴ Ω cm with a maximum mobility of ∼90 cm² V⁻¹ s⁻¹ and a high carrier concentration of 4 × 10²⁰ cm⁻³.

中文翻译：

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利用分子束外延技术实现带隙大于3.0 eV的岩石盐Zn1-xCdxO薄膜的实现

我们已经长大的Zn _{1- X}镉_X O（ZnCdO）薄膜通过分子束外延在的α-Al ₂ ö ₃（0001）跨越0≤全部组合物范围的底物X ≤1.纤锌矿相在组合物观察到的X ≤0.44，而对于被观察到的岩盐相X ≥0.58。在0.44 < x <0.58的组成区域内，纤锌矿和岩盐相共存。在在相变到RS X〜0.55，光隙急剧增加至> 3.0电子伏特。RS-ZnCdO合金在x处实现了3.0 eV的大光学间隙（本征间隙为2.7 eV）。约0.6。Cd含量低的RS相的稳定性可以归因于低温MBE工艺。由于相变，在混合相区域中观察到了带隙能量的上移，并且最大的带隙能量在WZ（x = 0）中为3.27 eV，在RS（x = 0.6）中为3.0 eV。相。RS-ZnCdO薄膜的电阻率低至5×10 ^-4Ωcm，最大迁移率约为90 cm ² V ^-1 s ^-1，而载流子浓度高，约为4×10 ²⁰ cm ^-3。