Photoconductive terahertz detectors with 105 dB peak dynamic range made of rhodium doped InGaAs

Rhodium (Rh)-doped In0.53Ga0.47As grown by gas-source molecular beam epitaxy is investigated as a terahertz (THz) detector antenna for optical excitation at 1550nm. The 4d transition metal rhodium acts as a deep level and ultrafast trapping center. At a doping concentration around 8x10(19)cm(-3), InGaAs:Rh exhibits ideal properties for application as a THz antenna: an ultrashort carrier lifetime below 200 fs in combination with a mobility of 1010cm(2)/Vs. The THz detectors fabricated from this sample show a record peak dynamic range of 105dB and a bandwidth of up to 6.5THz.