Amorphous Semiconductors. Part 1. Photoconductivity, Electroreflectance, and Electron Microscopy in Amorphous Germanium.
Abstract
The spectral dependence of photoconductivity in amorphous Ge is consistent with optical absorption measured on films grown under identical conditions; both disappear below 0.5 to 0.6 eV, and the photoconductivity threshold reproduces the effect of substrate temperature on the absorption threshold. Electroreflectance measurements on disordered Ge reported two years ago allowed the interpretation that the E sub o, E sub o + Delta sub o doublet is still present in the completely amorphous state. It is demonstrated that the electroreflectance peak positions are determined entirely by interference effects in the thin-film sample and hence have no bearing on the electronic structure of amorphous Ge. Electron micrographs have been obtained that clearly show the existence of a void network in amorphous Ge films formed at substrate temperatures of 25 and 150 C, and the absence of a void network in films formed at higher substrate temperatures of 200 and 250 C. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1972
- Accession Number
- AD0904831
Entities
People
- John E. Fischer
- Klaus Heinemann
- Terence M. Donovan
Organizations
- Naval Air Weapons Station China Lake