The p3/2, Fano and piezo-Fano spectra of singly ionised zinc impurity in germanium
Observations have been made of the infrared absorption of singly ionised zinc (Zn') in germanium. A detailed P3/2 spectrum has been obtained which permits an accurate comparison with the corresponding spectra of group III and neutral zinc (Zn0) impurities in geranium and also with the theoretical binding energies of Zn'. The experimental scaling factors between the energy states of Zn' and group III impurities and between Zn' and Zn0 impurities are found to be - 4.2 and - 4.1, respectively. Excellent agreement is found between theory and experiment for the unambiguously identified transitions. Thermal generation of Zn' spectra has been observed and is discussed. In addition to the normal P3/2 series, a Fano P3/2 series is observed and its piezospectroscopic behaviour examined, with some fascinating results. The Fano series yields data about transitions which are weak, or even forbidden, in the parent series.