Fig. 7. Manipulation of DOS in semiconductors by defect engineering. (a) DOS of different concentration Al-doped WO₃. Reproduced with permission from ref. 43. Copyright 2019, Springer Nature. (b) DOS of simulated ultrathin WO₃ nanosheets. Reproduced with permission from ref. 69. Copyright 2021, John Wiley and Sons. (c) TDOS of WSe₂ with different W : Se atomic ratios. Reproduced with permission from ref. 105. Copyright 2018, John Wiley and Sons. (d) Illustrations of CT resonance processes in different MV–Ta₂O₅ complexes. Reproduced with permission from ref. 25. Copyright 2019, John Wiley and Sons.