Enhanced terahertz emission from impurity compensated GaSb

Abstract

We report femtosecond optically excited terahertz (THz) emission from tellurium doped GaSb at room temperature. The influence of the majority and minority carrier type and concentrations on the strength of the THz emission is investigated. Strong enhancement of THz emission in GaSb is observed as a result of compensation of native acceptors by tellurium donors. Surface field acceleration and the photo-Dember effect are identified as THz emission mechanisms in GaSb and modeled in dependence of the majority and minority carrier type and concentrations in our GaSb samples. THz emission from $p$-type GaSb is dominated by the photo-Dember effect whereas THz emission from $n$-type GaSb is dominated by surface field acceleration. The doping conditions under which THz emission is maximized are identified.