Chemistry and electronic structure of the H2 plasma passivated surface of CdTe

Publisher Website
Google Scholar
Abstract
The effects of low energy H2 plasma exposure on the surface defect chemistry and the electronic structure of CdTe were studied by synchrotron radiation soft x‐ray photoemission spectroscopy and optical emission spectroscopy as a function of substrate temperature. The low energy H2 plasma was generated with a commercial electron cyclotron resonance plasma source using pure H2 with the plasma exposure being performed at ambient temperature, 100 °C, and 200 °C. Plasma species were identified with optical emission spectroscopy. In situ photoemission measurements were acquired after each plasma exposure in order to observe changes in the valence band electronic structure as well as changes in the Cd 4d and Te 4d core lines. The results were correlated in order to relate the plasma species and characteristics to changes in surface defect chemistry and electronic structure. These measurements indicate that the H2 plasma exposure type converts the CdTe(100) surface from p‐ to n‐type and passivates defect states.