Photoluminescence and photocurrent mapping of Fe-doped InP wafers

Photoluminescence (PL) and photocurrent (PC) maps allow to observe the iron distribution in semiinsulating Fe-doped InP wafers. A comprehensive interpretation of these maps can only be done by modelling the PL and PC signal in order to understand what is the origin of the contrast in those maps. We present here a set of rate equations that provide numerical and approached results allowing to interpret the variations of both PC and PL at both microscopic and mesoscopic scales. The near band gap PL intensity is shown to decrease when the product [Fe³⁺]* [Fe²⁺] increases, while the extrinsic PC intensity (λ_exc=1.06 μm) increases for increasing compensation ratio [Fe³⁺]/ [Fe²⁺]. Several examples are shown where these results can be applied to understand the iron distribution in Liquid encapsulated Czochralski (LEC) Fe-doped InP wafers, the iron distribution around large inclusions, doping growth striations and crystal defects is discussed considering their PL and PC responses.