High-responsivity high-gain In0.53Ga0.47As-InP quantum-well infrared photodetectors grown using metal-organic vapor phase epitaxy

We report the growth and fabrication of bound-to-bound In_0.53Ga_0.47As-InP quantum-well infrared photodetectors using metal-organic vapor phase epitaxy. These detectors have a peak detection wavelength of 8.5 μm. The peak responsivities are extremely large with R_pk=6.9 A/W at bias voltage V_b=3.4 V and temperature T=10 K. These large responsivities arise from large detector gain that was found to be g_n=82 at V_b=3.8 V from dark current noise measurements at T=77 K and g_p=18.4 at V_b=3.4 V from photoresponse data at T=10 K. The background-limited temperature with F/1.2 optics is T_BLIP=65 K for 0b≤3.4 V. The highest value of peak detectivity is D_λ^*=5.4×10⁹ cm√Hz/W at V_b=2.9 V and T=77 K, while for TBLIP=65 K, the background-limited detectivity, which exhibits negligible bias dependence, is D_BLIP^*=3×10¹⁰ cm√Hz/W.