I am working on my thesis for my masters in physics, and am running into some issues while trying to gather an IR spectrum of my hydrogenated amorphous silicon (a-Si). I am depositing my films using PECVD onto a glass microscope slide substrate. The films I have used so far have been 0.2-0.4 μm in thickness. The piece of equipment I am using right is a Thermo Scientific Nicolet iS10 FTIR Spectrometer. What I am encountering is essentially zero signal. I am not seeing any absorption of IR by my film. The professor I am working with and I think the reason may be because I do not have good contact with the surface of my film and the Ge crystal in the machine because the films and substrate are to rigid or because my film so far have been to thin. I would like to know if anyone has any suggestions for me on taking FTIR spectrum of amorphous silicon thin films or of thin film materials in general. Thank you very much for your time.