Thermally induced hole-electron competition in photorefractive InP:Fe due to the Fe2+ excited state

Abstract : The photorefractive coupling gain is limited in InP:Fe even if there is no direct hole‐electron competition. One has to take into account the excited state of Fe2+ (5T2) with its strong thermal emission(1/βth≂100 ns). This leads to an indirect hole‐electron competition mechanism and helps to explain experimental results. This coupling gain reduction is inherent to the nature of the Fe dopant in InP for wavelengths below 1.2 μm and temperature above 170 K.