Photoemission in the 1-2 Micron Range
Abstract
Research has begun on a GaAs/Ge device designed to have photoemission sensitivity into the 1-2 micron range. The device consists of a thin GaAs epitaxial layer vapor-phase grown on a p-n Ge junction. The p-n junction is reverse biased, and the GaAs is vacuum activated with Cs-O to negative electron affinity in operation. The p+-GaAs provides an effective biasing contact for the Ge p-n junction and allows photo-excited electrons to diffuse through into vacuum. Work during this first quarter has resulted in good quality epitaxial growth of GaAs on Ge. A one-micron thick GaAs/Ge sample has been vacuum activated to almost 1000 microamp/lm. The nature of As diffusion into Ge has been studied for the purpose of fabricating optimal Ge p-n junctions. Results of this experimental work combined with theoretical calculations indicate that our present substrate material is too highly doped for optimal device performance. Overall, the experimental results on GaAs and our calculations show that this device still looks most promising for 1-2 micron photoemission.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 16, 1972
- Accession Number
- AD0910216
Entities
People
- Herman F. Gossenberger
- John S. Escher