Large-area terahertz emitters based on GaInAsN

We present large-area emitters based on GaInAsN which show efficient THz emission for excitation wavelengths up to 1.35 µm. The substrate material consists of a 1000 nm Ga1-yInyAs1-xNx (y = 0.11 and x = 0.04) layer grown by molecularbeam epitaxy on semi-insulating GaAs. On top there is an additional GaAs/Al0.3Ga0.7As heterostructure with thicknesses of 5 nm for the GaAs and 60 nm for the AlGaAs layer, respectively. Transmission measurements with a Fourier transform spectrometer reveal a bandgap corresponding to a wavelength of 1.5 µm. The resistance of a complete device with an active area of 1 mm2 is 0.3 M ohm. This allows operation with high bias fields (30 kV/cm) without being limited by heating.