Radiative energy conversion device - having pn junction and surface layer with concn gradient to vary forbidden band width

摘要

Radiation energy conversion device comprises =2 regions of opposite conductivity types forming a pn junction, the first region being on the side of the face receiving the incident beam, at least the surface layer of the first region being made of a cpd. of wider forbidden energy gap than the material of the second region, the materials being III-V cpds., and is characterised in that the first region is n-type and the second is p type and of thickness greater than the electron diffusion path length, and in that the concentration of one of the components of the surface layer increases progressively through the thickness of this layer in such a direction that the width of the forbidden energy band increases progressively in the direction opposite to that of the incident radiation.