AVS 58th Annual International Symposium and Exhibition
    Energy Frontiers Focus Topic Thursday Sessions
       Session EN-ThP

Paper EN-ThP19
Investigating CdTe/CdS/TCO Inter-diffusion by AES and XPS

Thursday, November 3, 2011, 6:00 pm, Room East Exhibit Hall

Session: Energy Frontiers Poster Session
Presenter: L. Le Tarte, General Electric, Global Research Center
Authors: L. Le Tarte, General Electric, Global Research Center
A. Barbuto, General Electric, Global Research Center
J. Cournoyer, General Electric, Global Research Center
K. Dovidenko, General Electric, Global Research Center
H. Piao, General Electric, Global Research Center
Correspondent: Click to Email
CdTe has recently received a lot of attention as the material of choice for thin film solar cells as it converts light to electricity more cost effectively than traditional semiconductors and is compatible with manufacturing scale-up. An in-depth understanding of film composition, morphology and interface integrity is critical for CdTe thin film process development. Clear depth profiles of the buried layers by Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) are difficult to obtain due to the rough, and thick (~3µm ± 0.5µm), upper CdTe layer. Sputtering through this layer leads to broadened depth profile interfaces which reduces information about inter-diffusion. We have developed a polishing method to thin and smooth this layer prior to analysis. In this poster we will present how this method has improved the Auger depth resolution and therefore the understanding of inter-diffusion between the CdTe, CdS and TCO layers. A novel FIB preparation method for Auger will also be discussed. XPS imaging analyses on AES sputter crater sidewalls provides additional chemical information about the buried layers and interfaces.