Picosecond photoconductivity using a graded bandgap Al/sub x/Ga/sub 1-x/As active detecting layer

Abstract

This paper presents a concept where improved responsivity for picosecond photoconductors is achieved by utilizing a graded bandgap AI.oal.,As active detecting layer grown on a high defect density, low temperature GaAs layer by MBE. By taking advan tage of the superior tranSport propenies of the graded AI, Ga,.,As layer, order of magnitude improvement in responsivity has been demontrated, along with 2-6 times improvement in peak photo current response.