Sullivan, J.T.; Wilks, R.G.; Winkler, M.T.; Weinhardt, L.; Recht, D.; Said, A.J.; Newman, B.K.; Zhang, Y.; Blum, M.; Krause, S.; Yang, W.L.; Heske, C.; Aziz, M.J.; Bär, M.; Buonassisi, T.: Soft x-ray emission spectroscopy studies of the electronic structure of silicon supersaturated with sulfur. Applied Physics Letters 99 (2011), p. 142102/1-3
10.1063/1.3643050
Abstract:
We apply soft X-ray emission spectroscopy (XES) to measure the electronic structure of crystalline silicon supersaturated with sulfur (up to 0.6 at%), a candidate intermediate-band solar cell material. Si L2,3 emission features are observed above the conventional Si valence band maximum, with intensity scaling linearly with S concentration. The lineshape of the S-induced features change across the insulator-to-metal transition,1 indicating a significant modification of the local electronic structure concurrent with the change in macroscopic electronic behavior. The relationship between Si L2,3 XES spectral features and the anomalously high sub-band gap infrared absorption is discussed.