Influence of oxygen partial pressure on the physical behaviour of CdO films prepared by activated reactive evaporation

Optical characterization of thermally evaporated thin CdO films

“…The results are given in table 1. These results are in agreement with the theoretical calculations of the band structure [30] and agree within ±0.1eV with the previous values, calculated for films prepared by other methods [7,13,21,29,31]. The low-energy tail in α(E) curve is due to the transitions from valence states to the extended conduction band Urbach states [32], which is attributed to local mechanical stress produced by impurities and structural defects.…”

“…It is clear that, the prepared films have the <111> preferred orientation. This is in accordance with the reports on CdO films prepared by dc magnetron reactive sputtering [10], dc sputtering [19] and activated reactive evaporation [13,20,21]. It was found that the film preferred orientation depends on the deposition method used; the <120> orientation was reported in the ion beam sputtering [22] and spray pyrolysis films [9].…”

The shift in the optical band-gap of cadmium oxide as chemical potential minus optical potential

“…Perhaps the most known application of CdO is as transparent contact in solar cells and as antireflection coating. On the other hand, we have to mention that this oxide has been investigated experimentally with quite satisfactory results [1][2][3][4][5][6][7][8][9][10][11][12] and by elaborating successfully theoretical-analytical approaches [13][14][15][16][17]. But, unfortunately, some works as, for instance, Refs.…”

“…The shift in the optical band-gap exhibited by some oxides as, for example, CdO, known in the current literature as the Burstein-Moss effect, is directly related to the subject of the present letter. At room temperature, an energy bandgap shift from 2.3 eV to 2.7 eV was measured in cadmium oxide [3] while a shift from 2.40 eV to 2.42 eV was observed [4] as well as from 2.32 eV up to 2.52 eV [1]. The aforementioned shift varies with the partial pressure of oxygen relative to the growth of CdO crystals and also changes with temperature.…”

Effect of rapid thermal annealing on Zn1‐xCdxO layers grown by radio‐frequency magnetron co‐sputtering

“…Therefore, the bandgap of ZnO can be modulated from UV emission to green spectra by alloying with cadmium oxide (CdO) of 2.3 eV [8]. For the quantum-well (QW) structure of ZnCdO/ZnO, the zinc cadmium oxide (ZnCdO) alloy can be utilized as the active layer combined with ZnO barrier.…”